@inproceedings{FuhrmannNiemetz, author = {Fuhrmann, Thomas and Niemetz, Michael}, title = {Analysis and Improvement of Engineering Exams Toward Competence Orientation by Using an AI Chatbot}, series = {Towards a Hybrid, Flexible and Socially Engaged Higher Education: Proceedings of the 26th International Conference on Interactive Collaborative Learning (ICL2023), Volume 1}, booktitle = {Towards a Hybrid, Flexible and Socially Engaged Higher Education: Proceedings of the 26th International Conference on Interactive Collaborative Learning (ICL2023), Volume 1}, publisher = {Springer Nature}, address = {Cham}, isbn = {9783031519789}, issn = {2367-3370}, doi = {10.1007/978-3-031-51979-6_42}, pages = {403 -- 411}, abstract = {ChatGPT is currently one of the most advanced general chatbots. This development leads to diverse challenges in higher education, like new forms of teaching and learning, additional exam methods, new possibilities for plagiarism, and many more topics. On the other side with the development of advanced AI tools, pure knowledge will be less and less important, and demands from industry will change toward graduates with higher competencies. Education has therefore to be changed from knowledge-centered toward competence centered. The goal of this article is to use ChatGPT for analyzing and improving the competence orientation of exams in engineering education. The authors use ChatGPT to analyze exams from different engineering subjects to evaluate the performance of this chatbot and draw conclusions about the competence orientation of the tested exams. The obtained information is used to develop ideas for increasing the competence orientation of exams. From this analysis, it is visible that ChatGPT gives good performance mainly where knowledge is tested. It has, however, much more problems with transfer questions or tasks where students need creativity or complex insights for finding new solutions. Based on this result, exams and also lectures can be optimized toward competence orientation.}, language = {en} } @article{SalamaKouDawoudetal., author = {Salama, Amgad and Kou, Jisheng and Dawoud, Belal and Simonson, Carey}, title = {A modeling approach for capillary-driven flow of a wetting fluid in a rectangular open microchannel of arbitrary axisymmetric width profile}, series = {International Journal of Thermal Sciences}, volume = {195}, journal = {International Journal of Thermal Sciences}, publisher = {Elsevier}, issn = {1290-0729}, doi = {10.1016/j.ijthermalsci.2023.108622}, pages = {17}, abstract = {Microchips are intensively used in almost all nowadays electronic devices. With the continuous advancement of our technologies, they get smaller in size than ever before. They generate high-intensity heat loads that need to be transported effectively such that they may function properly. Heat pipes have proven to be very effective in transporting relatively large heat loads from miniature components. They are of seamless structure that involves a working fluid capable of evaporation and condensation at the working temperature of the electronic chips. The working fluid is derived to move from the condenser to the evaporator via multiple microgrooves using capillary forces. It is important that the condensate reaches the evaporator at a proper rate such that no dry-out or flooding occur. In this work, we are particularly interested in the case of capillary-driven flows in rectangular microchannels. A generalized model is developed that works for axe-symmetric rectangular channels of arbitrary, moderately varying width profiles. It also accounts for any contrast of viscosity between the liquid and the vapor under isothermal conditions. The model shows to reduce to the special case of imbibition in straight and uniform microchannels, for which comparisons with experimental and modeling works show an excellent match. Cases representing linearly and quadratically varying converging/diverging width profiles have been explored. It is found that the viscosity ratio has a significant influence on the rate at which the meniscus advances. The model also negates the common practice found in the literature of using the formula developed for imbibition rates in capillary tubes for rectangular microchannels by replacing the diameter of the tube with the hydraulic diameter. It is also found that the channel profile has an influential effect on the imbibition rates. For tapered microchannels, the capillary force increases along the channel length while it decreases for diverging ones. It is interestingly demonstrated that, for quadratically tapered microchannel, the speed of the meniscus increases towards the end of the microchannel compared with linearly varying microchannels. On the other hand, for diverging microchannels, the speed of the meniscus decreases due to the increase in the cross-sectional area. Computational fluid dynamics (CFD) analysis has been conducted to provide a framework for confirmation and verification for which very good match has been established, which builds confidence in the modeling approach.}, language = {en} } @unpublished{SchummAbdelKhalekBrownetal., author = {Schumm, Leon and Abdel-Khalek, Hazem and Brown, Tom and Ueckerdt, Falko and Sterner, Michael and Fioriti, Davide and Parzen, Max}, title = {The impact of temporal hydrogen regulation on hydrogen exporters and their domestic energy transition}, publisher = {Research Square Platform LLC}, doi = {10.21203/rs.3.rs-4285425/v1}, abstract = {As global demand for green hydrogen rises, potential hydrogen exporters move into the spotlight. However, the large-scale installation of on-grid hydrogen electrolysis for export can have profound impacts on domestic energy prices and energy-related emissions. Our investigation explores the interplay of hydrogen exports, domestic energy transition and temporal hydrogen regulation, employing a sector-coupled energy model in Morocco. We find substantial co-benets of domestic climate change mitigation and hydrogen exports, whereby exports can reduce domestic electricity prices while mitigation reduces hydrogen export prices. However, increasing hydrogen exports quickly in a system that is still dominated by fossil fuels can substantially raise domestic electricity prices, if green hydrogen production is not regulated. Surprisingly, temporal matching of hydrogen production lowers domestic electricity cost by up to 31\% while the effect on exporters is minimal. This policy instrument can steer the welfare (re-)distribution between hydrogen exporting firms, hydrogen importers, and domestic electricity consumers and hereby increases acceptance among actors.}, language = {en} } @inproceedings{GaertnerRankHeberletal., author = {G{\"a}rtner, Sebastian and Rank, Daniel and Heberl, Michael and Gaderer, Matthias and Sterner, Michael}, title = {Integration of Power-To-Methane into Glass Melting Processes}, series = {Proceedings of the International Renewable Energy Storage Conference (IRES 2022)}, volume = {16}, booktitle = {Proceedings of the International Renewable Energy Storage Conference (IRES 2022)}, publisher = {Atlantis Press}, issn = {2589-4943}, doi = {10.2991/978-94-6463-156-2_12}, pages = {147 -- 161}, abstract = {The glass industry is facing increased challenges regarding climate protection targets and rising energy costs. The integration of renewable energy including conversion and storage is a key for both challenges in this energy-intensive industrial sector, which has been mainly relying on fossil gas so far. The options considered to this point for reducing CO2 emissions and switching to a renewable energy supply involve far-reaching changes of the established melting processes. This entails significant risks in terms of influences on glass quality and stable production volumes. The presented approach for the integration of a Power-to-Methane (PtM) system into the glass industry is a completely new concept and has not been considered in detail before. It allows the use of established oxyfuel melting processes, the integration of fluctuating renewable energy sources and a simultaneous reduction of CO2 emissions by more than 78\%. At the same time, natural gas purchases become obsolete. A techno-economic evaluation of the complete PtM process shows, that 1,76 €/m3 or 1,26 €/kg synthetic natural gas are possible with renewable energy supply. Using electricity from the energy grid would require electricity prices < 0,126 €/kWh to allow cost competitive PtM processes in the glass industry. Such electricity prices could be achieved by electricity market-based optimization and operation of the PtM system. This operation strategy would require AI-based algorithms predicting availabilities and prices on future-based markets.}, language = {en} } @article{GamischEttengruberGadereretal., author = {Gamisch, Bernd and Ettengruber, Stefan and Gaderer, Matthias and Dawoud, Belal}, title = {Dynamic simulation of isothermal and non-isothermal reduction and oxidation reactions of iron oxide for a hydrogen storage process}, series = {Renewable and Sustainable Energy}, volume = {1}, journal = {Renewable and Sustainable Energy}, number = {1}, publisher = {ELSP, International Open Science Platform}, doi = {10.55092/rse20230004}, abstract = {This work aims first to develop a dynamic lumped model for the isothermal reactions of hydrogen/steam with a single iron oxide/iron pellet inside a tubular reactor and to validate the model results against the experimental reaction kinetic data with the help of our STA device. To describe the temporal change in mass, and consequently, the temporal heat of reaction, the shrinking core model, based on the geometrical contracting sphere, is applied. It turned out that, the simulation model can reproduce the experimental, temporal concentration and temperature-dependent conversion rates with a maximum deviation of 4.6\% during the oxidation reactions and 3.1\% during the reduction reactions. In addition, a measured isothermal storage process comprising one reduction and one oxidation phase with a holding phase in between on a single reacting pellet could be reproduced with a maximum absolute deviation in the conversion rate of 1.5\%. Moreover, a lumped, non-isothermal simulation model for a pelletized tubular redox-reactor including 2kg of iron oxide pellets has been established, in which the heat of reaction, heat transfer to the ambient and heat transfer between the solid and gas phases are considered. The temporal courses of the outlet gas concentration as well as the temperatures of the gas stream and the solid material at a constant input gas flow rate and a constant reacting gas inlet concentration but different input gas temperatures are estimated. Because of the endothermic nature of the reduction reaction, the inlet reacting gas temperature shall be kept high to prevent the severe temperature drop in the solid phase and, consequently, the significant reduction of the reaction rate. Contrary to that, the oxidation process requires lower input gas temperatures to avoid the excessive overheating of the reaction mass and, consequently, the sintering of the reacting pellets. Finally, five of the previous reactors have been connected in series to explore the influence of the changing inlet gas temperatures and concentrations on the dynamic performance of each storage mass.}, language = {en} } @article{WalterSchwanzerHagenetal., author = {Walter, Stefanie and Schwanzer, Peter and Hagen, Gunter and Rabl, Hans-Peter and Dietrich, Markus and Moos, Ralf}, title = {Soot Monitoring of Gasoline Particulate Filters Using a Radio-Frequency-Based Sensor}, series = {Sensors}, volume = {23}, journal = {Sensors}, number = {18}, publisher = {MDPI}, issn = {1424-8220}, doi = {10.3390/s23187861}, pages = {1 -- 19}, abstract = {Owing to increasingly stringent emission limits, particulate filters have become mandatory for gasoline-engine vehicles. Monitoring their soot loading is necessary for error-free operation. The state-of-the-art differential pressure sensors suffer from inaccuracies due to small amounts of stored soot combined with exhaust gas conditions that lead to partial regeneration. As an alternative approach, radio-frequency-based (RF) sensors can accurately measure the soot loading, even under these conditions, by detecting soot through its dielectric properties. However, they face a different challenge as their sensitivity may depend on the engine operation conditions during soot formation. In this article, this influence is evaluated in more detail. Various soot samples were generated on an engine test bench. Their dielectric properties were measured using the microwave cavity perturbation (MCP) method and compared with the corresponding sensitivity of the RF sensor determined on a lab test bench. Both showed similar behavior. The values for the soot samples themselves, however, differed significantly from each other. A way to correct for this cross-sensitivity was found in the influence of exhaust gas humidity on the RF sensor, which can be correlated with the engine load. By evaluating this influence during significant humidity changes, such as fuel cuts, it could be used to correct the influence of the engineon the RF sensor.}, language = {en} } @article{RillSchuderer, author = {Rill, Georg and Schuderer, Matthias}, title = {A Second-Order Dynamic Friction Model Compared to Commercial Stick-Slip Models}, series = {Modelling}, volume = {4}, journal = {Modelling}, number = {3}, publisher = {MDPI}, issn = {2673-3951}, doi = {10.3390/modelling4030021}, pages = {366 -- 381}, abstract = {Friction has long been an important issue in multibody dynamics. Static friction models apply appropriate regularization techniques to convert the stick inequality and the non-smooth stick-slip transition of Coulomb's approach into a continuous and smooth function of the sliding velocity. However, a regularized friction force is not able to maintain long-term stick. That is why dynamic friction models were developed in recent decades. The friction force depends herein not only on the sliding velocity but also on internal states. The probably best-known representative, the LuGre friction model, is based on a fictitious bristle but realizes a too-simple approximation. The recently published second-order dynamic friction model describes the dynamics of a fictitious bristle more accurately. It is based on a regularized friction force characteristic, which is continuous and smooth but can maintain long-term stick due to an appropriate shift in the regularization. Its performance is compared here to stick-slip friction models, developed and launched not long ago by commercial multibody software packages. The results obtained by a virtual friction test-bench and by a more practical festoon cable system are very promising. Thus, the second-order dynamic friction model may serve not only as an alternative to the LuGre model but also to commercial stick-slip models.}, language = {en} } @inproceedings{Rill, author = {Rill, Georg}, title = {Real-Time capable Multibody Model of dual Truck Front Axles}, series = {Proceedings of DINAME 2023 - Selected Papers of the XIX International Symposium on Dynamic Problems of Mechanics, 26 Feb - 03 Mar 2023, Piren{\´o}polis, Brazil}, booktitle = {Proceedings of DINAME 2023 - Selected Papers of the XIX International Symposium on Dynamic Problems of Mechanics, 26 Feb - 03 Mar 2023, Piren{\´o}polis, Brazil}, editor = {Fleury, Agenor de T.}, publisher = {Springer}, abstract = {Dual front steering axles are quite common in multi-axled heavy duty trucks. In standard layouts of such axle combinations, the steer motions of the wheels depend not only on the rotation of the steering wheel but also on the movements of the axles. As a consequence, the model complexity of the steering system should match with the complexity of the suspension model. The development of new technologies like advanced driver assistance systems or autonomous driving can only be accomplished efficiently using extensive simulation methods. Such kind of applications demand for computationally efficient vehicle models. This paper presents a steering system model for dual front axles of heavy duty trucks which supplements the suspension model of the axles. The model takes the torsional compliance of the steering column as well as the stiffness of the tie rods and the coupling rod into account. A quasi-static solution provides a straight forward computation including the partial derivatives required for an efficient implicit solver. The steering system model matches perfectly with comparatively lean, but sufficiently accurate multibody suspension models.}, language = {en} } @techreport{ZacherlWopperMieslingeretal., author = {Zacherl, Florian and Wopper, Christoph and Mieslinger, Johann and Peis, Michael and Rabl, Hans-Peter}, title = {Schlussbericht zum Verbundvorhaben NAMOSYN: Nachhaltige Mobilit{\"a}t durch synthetische Kraftstoffe}, address = {Regensburg}, pages = {156}, abstract = {Im Labor f{\"u}r Verbrennungsmotoren und Abgasnachbehandlung der OTH-Regensburg sollten im Zuge des NAMOSYN-Projektes zwei Vertreter klimaneutraler Kraftstoffe an verschiedenen Systempr{\"u}fst{\"a}nden (Motor-, Einspritzpr{\"u}fstand, optisch zug{\"a}ngliche Einspritzkammer, …) und mit Hilfe von Simulationsmethoden f{\"u}r den Einsatz in bestehenden Verbrennungsmotoren untersucht werden. Synthetische Kraftstoffe aus der Gruppe der Oxymethylenether (OME) stellen eine CO2-neutrale Alternative zu fossilem Dieselkraftstoff dar. F{\"u}r Ottomotoren wurde untersucht, ob der synthetische Kraftstoff DMC/MeFo (Dimethylcarbonat \& Methylformiat) einen Ersatz f{\"u}r Ottokraftstoff darstellen kann, bzw. eine Drop-In-F{\"a}higkeit gegeben ist. Die OTH Regensburg bearbeitete 2 unabh{\"a}ngige Teilvorhaben zur motorischen Testung von synthetischen Kraftstoffen: „FC 1A: Motorische Testung von OME" und „FC 2: Untersuchung von C1-Oxygenaten f{\"u}r Ottomotoren". Die Projektlaufzeit betrug 3,5 Jahre, inkl. kostenneutraler Verl{\"a}ngerung um 6 Monate aufgrund der Corona-Pandemie. Im FC1A "AP2-Nachr{\"u}stung Dieselmotoren" der OTH Regensburg lag der Fokus auf der Erforschung der Potentiale und der Umr{\"u}stung eines Einzylinder-Dieselmotors mit Pumpe-Leitung-D{\"u}se-(PLD)-Einspritzsystem des Projektpartners Motorenfabrik Hatz GmbH und Co. KG f{\"u}r OME-Betrieb. Im AP2.1 wurden umfangreiche Daten gesammelt und Simulationsmodelle des Motors und PLD-Einspritzsystems erstellt und mit Dieselkraftstoff und OME validiert. Nachfolgend wurden Parameterstudien zur Geometrie des Einspritzsystems und der physikalischen Eigenschaften von OME durchgef{\"u}hrt. In AP2.2 und AP2.3 wurden umfangreiche Untersuchungen an einem Motor- und Einspritzsystempr{\"u}fstand mit Diesel und OME durchgef{\"u}hrt und der Steuerger{\"a}tedatensatz f{\"u}r den OME-Betrieb optimiert. Die Ergebnisse zeigen, dass die Umstellung des Kraftstoffs auf OME, insbesondere bei einfachen Motoren mit rudiment{\"a}rer Einspritztechnik und ohne Mittel zur NOx-Reduzierung (keine AGR oder SCR), ein enormes Potenzial zur Steigerung des Wirkungsgrads bei gleichzeitiger Reduzierung aller regulierten Schadstoffe (NOx, 𝑃N, 𝑃M, CO und 𝑉OC) er{\"o}ffnet. Die Ergebnisse und generierten Simulationsmodelle unterst{\"u}tzen eine schnelle Serienentwicklung und Einf{\"u}hrung von OME-Umr{\"u}stl{\"o}sungen. In FC 2 werden die vielversprechenden Kraftstoffe Methylformiat (MeFo) und Dimethylcarbonat (DMC) motorisch getestet. Untersuchungen am Kraftstoffsystem und wichtigen Komponenten dienen als Grundlage f{\"u}r das AP3. Im AP3 wird die Machbarkeit der DMC/MeFo-Verbrennung am Vollmotor demonstriert und die erwarteten Emissionsvorteile gegen{\"u}ber herk{\"o}mmlichen Ottokraftstoffen gezeigt. Abweichend von der urspr{\"u}nglichen Planung werden an der OTH Regensburg Kraftstoffblends aus Benzin und MeFo untersucht, um den Einsatzbereich des Kraftstoffs zu erweitern. In AP5 werden potentielle Mischungsverh{\"a}ltnisse analysiert und die Eigenschaften der ausgew{\"a}hlten Kraftstoffmischungen an einem Einspritzratenpr{\"u}fstand, an der Einspritzkammer und am Vollmotor untersucht. Es werden Einspritzverhalten, Gemischaufbereitung und Abgasemissionen bewertet. Zudem wird eine Kraftstoffmischanlage entwickelt und ein optischer Zugang am Vollmotor erm{\"o}glicht. Eine {\"O}lverd{\"u}nnungsmesstechnik wird eingesetzt, um den Kraftstoffeintrag ins Motor{\"o}l zu untersuchen}, language = {de} } @article{MikhaeilGadererDawoud, author = {Mikhaeil, Makram and Gaderer, Matthias and Dawoud, Belal}, title = {On the application of adsorber plate heat exchangers in thermally driven chillers}, series = {Applied Thermal Engineering}, volume = {220}, journal = {Applied Thermal Engineering}, publisher = {Elsevier}, doi = {10.1016/j.applthermaleng.2022.119713}, abstract = {The effect of both heat and mass transfer characteristic lengths (HTCL, MTCL) of two different adsorber plate heat exchangers (APHE), for application in an adsorption chiller, on the adsorption and desorption kinetics is investigated. Three representative test frames (TF1-TF3) are prepared to examine small-scale adsorbent samples of the microporous silica gel (Siogel of Oker-Chemie, Germany) applying the volumetric large-temperature-jump methodology at different operating conditions. Based on the obtained kinetic data, an analytical model has been developed to predict the specific cooling power (SCP) and the coefficient of performance (COP) of a single-bed adsorption chiller comprising the studied APHEs. It turned out that, within the tested range of HTCL and MTCL, it can be concluded that, the adsorption kinetics are mainly influenced by the MTCL, while the desorption kinetics are dominated by the HTCL of the adsorbent domain. Applying Siogel as loose pellets inside a newly introduced APHE results in of 423.3 and 182.7 W⋅kg-1, at the evaporator temperatures of 15 °C and 5 °C, respectively. Herein, the condenser and adsorber-end temperatures amount to 30 °C and the desorption-end temperature to 90 °C. The corresponding s amount to 0.50 and 0.40, respectively, which represent quite promising results for further design optimizations.}, language = {en} } @inproceedings{TremmelNaglerKutteretal., author = {Tremmel, Florian and Nagler, O. and Kutter, C. and Holmer, Rainer}, title = {Smart Cantilever Probe with Integrated Force and Acoustic Emission Sensor}, series = {2023 IEEE SENSORS, Vienna, Austria, 10/29/2023 - 11/1/2023}, booktitle = {2023 IEEE SENSORS, Vienna, Austria, 10/29/2023 - 11/1/2023}, publisher = {IEEE}, isbn = {979-8-3503-0387-2}, doi = {10.1109/SENSORS56945.2023.10325021}, pages = {1 -- 4}, abstract = {Acoustic emission (AE) testing recently found its application in the wafer testing sector of the semiconductor industry. To find out the mechanical robustness of semiconductor devices, contact pads on the chip surface are intentionally overstressed with an indenter tip and the appearing oxide cracks are detected with help of the generated AE signals. This is done in a customized test bench with a patented sensor-indenter system. This paper presents an improved version of the measurement setup that solves certain disadvantages of it and can be used in a standard wafer prober. The main components of the developed sensor system are a strain gauge for contact force measurement and a piezoelectric sensor element for AE signal detection. Both components are integrated on a cantilever beam which has an exchangeable indenter tip at its free end. The cantilever probe is electrically conductive to enable electrical tests via the indenter tip. This smart sensor-cantilever combination (SCC) can be mounted with several adapter components on a carrier plate to place it in a wafer prober. For both sensor elements amplifier circuits are developed to enhance their signal-to-noise ratios (SNRs). A prototype setup is shown together with simulated and experimental results to demonstrate its performance. The mechanical properties of the cantilever, as well as the force sensor and the AE crack signals, already fulfill the requirements for an implementation in a wafer prober. To further improve the sensor resolutions and detection limits, several optimizations regarding the design of the SCC are in progress.}, language = {en} } @article{HofrichterRankHeberletal., author = {Hofrichter, Andreas and Rank, Daniel and Heberl, Michael and Sterner, Michael}, title = {Determination of the optimal power ratio between electrolysis and renewable energy to investigate the effects on the hydrogen production costs}, series = {International Journal of Hydrogen Energy}, volume = {48}, journal = {International Journal of Hydrogen Energy}, number = {5}, publisher = {Elsevier}, issn = {0360-3199}, doi = {10.1016/j.ijhydene.2022.09.263}, pages = {1651 -- 1663}, abstract = {Green hydrogen via renewable powered electrolysis has a high relevance in decarbonization and supply security. Achieving economically competitive hydrogen production costs is a major challenge in times of an energy price crisis. Our objective is to show the economically optimal installed capacity of electrolysers in relation to wind and solar power so swift and credible statements can be made regarding the system design. The ratio between renewable generation and electrolysis power as well as scaling effects, operating behaviour and development of costs are considered. Hydrogen production costs are calculated for four exemplary real PV and wind sites and different ratios of electrolysis to renewable power for the year 2020. The ideal ratio for PV systems is between 14\% and 73\% and for wind between 3.3\% and 143\% for low and high full load hours. The lowest hydrogen production costs are identified at 2.53 €/kg for 50 MW wind power and 72 MW electrolysis power. The results provide plant constructors the possibility to create a cost-optimized design via an optimum ratio of electrolysis to renewable capacity. Therefore, the procedures for planning and dimensioning of selected systems can be drastically simplified.}, language = {en} } @article{KeinerThomaBogdanovetal., author = {Keiner, Dominik and Thoma, Christian and Bogdanov, Dmitrii and Breyer, Christian}, title = {Seasonal hydrogen storage for residential on- and off-grid solar photovoltaics prosumer applications: Revolutionary solution or niche market for the energy transition until 2050?}, series = {Applied Energy}, volume = {340}, journal = {Applied Energy}, publisher = {Elsevier}, doi = {10.1016/j.apenergy.2023.121009}, pages = {17}, abstract = {Appropriate climate change mitigation requires solutions for all actors of the energy system. The residential sector is a major part of the energy system and solutions for the implementation of a seasonal hydrogen storage system in residential houses has been increasingly discussed. A global analysis of prosumer systems including seasonal hydrogen storage with water electrolyser, hydrogen compressor, storage tank, and a fuel cell studying the role of such a seasonal household storage in the upcoming decades is not available. This study aims to close this research gap via the improved LUT-PROSUME model, which models a fully micro sector coupled residential photovoltaic prosumer system with linear optimisation for 145 regions globally. The modelling of the cost development of hydrogen storage components allows for the simulation of a residential system from 2020 until 2050 in 5-year steps in hourly resolution. The systems are cost-optimised for either on- or off-grid operation in eight scenarios including battery electric vehicles, which can act as an additional vehicle-to-home electricity storage for the system. Results show that implementation of seasonal hydrogen systems only occurs in least cost solutions in high latitude countries when the system is forced to run in off-grid mode. In general, a solar photovoltaic plus battery system including technologies that can cover the heat demand is the most economic choice and can even achieve lower cost than a full grid supply in off-grid operation for most regions until 2050. Additional parameters including the self-consumption ratio, the demand cover ratio, and the heat cover ratio can therefore not be improved by seasonal storage systems if economics is the main deciding factor for a respective system. Further research opportunities and possible limitations of the system are then identified.}, language = {en} } @article{DePremekMottok, author = {De, Sangita and Premek, Brada and Mottok, J{\"u}rgen}, title = {Derivation of Optimized Threshold of Semantic Alignment Metrics for Intepretation of Interoperability and Reusability of Cross-enterprise Vehicle Service Interface Models}, series = {Informatica}, volume = {47}, journal = {Informatica}, number = {7}, publisher = {Slovenian Society Informatika}, issn = {0350-5596}, doi = {10.31449/inf.v47i7.4739}, abstract = {Over the past decade, cars have turned gradually into real cyber physical systems. The collaboration of services between the service-oriented, cross-enterprise vehicle application frameworks has increased to generate novel, smart and complicated vehicle services. Consequently, from an interoperability perspective, semantically mapping of vehicle service component's interface ontological models emerged as a big research interest in automotive application domain that manipulates several cross-enterprise synergy knowledge applications frameworks. The ontological metamodeling lays the foundation for building semantic bridge and exploring semantic associations between service components' interface models based on the domain knowledge for semantic interoperability. Also, several semantic quality metrics has been defined over time for the vehicle service interface ontological metamodels. The empirically evaluated values of these metrics can be used to assess progress in cross-enterprise interoperability between the service and the clients' APIs ontological models in vehicle domain. Despite potential benefits of semantic alignment quality metrics, the effective use of these metrics for vehicle service interface ontologies have proven elusive. Yes, such metrics can be used successfully for quantification, but then they mostly fail to provide adequate annotations in subsequent decision-making in the direction of semantic interoperability and reusability. The effective use of ontology semantic alignment quality metrics is basically hindered in the absence of the meaningful thresholds. In fact, the absence of an effective and meaningful threshold for the semantic similarity measure between various vehicle service interface ontological metamodels, motivates this research work which not only proposes a design approach to an optimized threshold for the semantic similarity metrics but also applies this threshold on few defined semantic alignment quality metrics. This paper also uses a real-world vehicle domain industrial case study to illustrate the design approach.}, language = {en} } @article{HuberHeindlSchlosseretal., author = {Huber, Lea and Heindl, Melanie and Schlosser, Marc and Pfitzner, Arno and Dawoud, Belal}, title = {On the Cycle Stability and Macroscopic Structure of Iron Oxide Pellets for Thermochemical Hydrogen Storage: Influence of Water Content during the Pelletizing Process}, series = {Applied Sciences}, volume = {13}, journal = {Applied Sciences}, number = {11}, publisher = {MDPI}, address = {16}, doi = {10.3390/app13116408}, abstract = {Hydrogen storage based on the repeated reduction and oxidation (redox) reactions of iron oxide/iron composites represents a promising technology. This work is dedicated to studying the influence of the amount of water added during the pelletizing process on the cycle stability and structure of iron oxide pellets. The storage composites were prepared from iron oxide (Fe2O3) and 10 wt.-\% support material (cement) with different amounts of water (18 and 33 wt.-\%) in a laboratory-scale pelletizing disk. To evaluate the cycle stability of the composites, the kinetics of the redox reactions were experimentally measured at 800 ∘ C in an atmosphere of 50\% N2 and 50\% H2 (reduction) or 50\% steam (oxidation), respectively. Moreover, the structure of the pellets was analyzed by micro-computed tomography scans. It turned out that pellets with higher water contents attained faster kinetics and a higher cycle stability. The sample with the least water content (18 wt.-\%) needed about 26 min and 19 min to reach a conversion rate of 80\% during the reduction and oxidation reactions of the sixth redox cycle, respectively. In contrast, the sample with the highest water content (33 wt.-\%) could achieve the same conversion rate after 18 min (reduction) and 13 min (oxidation) during the ninth redox cycle.}, language = {en} } @article{WalterSchwanzerHagenetal., author = {Walter, Stefanie and Schwanzer, Peter and Hagen, Gunter and Rabl, Hans-Peter and Dietrich, Markus and Moos, Ralf}, title = {Combined Ash and Soot Monitoring for Gasoline Particulate Filters Using a Radio-Frequency-Based Sensor}, series = {Emission Control Science and Technology}, journal = {Emission Control Science and Technology}, publisher = {Springer}, doi = {10.1007/s40825-023-00235-y}, pages = {9}, abstract = {Increasingly stringent emission limits have made particulate filters necessary for gasoline engines. Similar to diesel applications, gasoline particulate filters (GPFs) can be monitored by differential pressure measurement or by the radio-frequency-based filter diagnosis (RF sensor). In addition to measuring the soot loading, ash detection is critical for monitoring the GPF over the entire vehicle lifetime. Because the RF sensor detects the filter loading through a change in the dielectric properties of the GPF, it can detect not only soot but also ash. In diesel applications, the RF sensor has already demonstrated its potential for ash detection. To verify the feasibility of simultaneous ash and soot monitoring for GPFs, filters were loaded with ash on an engine test bench and measured on a lab test bench under defined synthetic exhaust gas conditions. By evaluating resonant modes, soot and ash could be clearly distinguished, as ash mainly affects the resonant frequency, while soot also changes the quality factor due to its high dielectric losses. However, higher soot loadings could not be detected by the resonant parameters, but instead by a frequency-averaged transmission signal. While the presence of ash caused an offset in this signal, its sensitivity to soot was not affected. Thus, the influence of ash can be corrected if the signal in the soot-free filter state is known, e.g., from the behavior of the resonant parameters. Therefore, even with a continuously increasing ash loading over the lifetime of a vehicle, an accurate soot detection is possible with the RF sensor.}, language = {en} } @unpublished{HeberlWithelmKauletal., author = {Heberl, Michael and Withelm, Christian and Kaul, Anja and Rank, Daniel and Sterner, Michael}, title = {Prospective Life Cycle Assessment of Biological Methanation in a Trickle-Bed Pilot Plant and a Potential Scale-Up}, publisher = {SSRN}, doi = {10.2139/ssrn.4635066}, abstract = {In this study, a pilot-scale trickle-bed reactor for biological methanation and various scale-up scenarios for 2023 and 2050 were investigated using LCA. A best- and worst-case scenario for technology development until 2050 was evolved using cross consistency analysis and morphological field, based on which the data for the ecological models were determined.The results show that the plant scale-up has a very positive effect on the ecological consequences of methanation. In the best-case scenario, the values are a factor of 23-780 lower than those of the actual plant today. A hot-spot analysis showed that especially electrolysis operation has a large impact on total emissions. The final Monte-Carlo simulation shows that the technology is likely to achieve a low GWP with a median of 104.0 kg CO2-eq / MWh CH4.}, language = {en} } @techreport{SoergelLudererEmelianovaetal., author = {S{\"o}rgel, Dominika and Luderer, Gunnar and Emelianova, Polina and Koch, Otto and Timpe, Christof and Bauer, Franz and Sterner, Michael}, title = {Kopernikus-Szenarienvergleich - Robuste Eigenschaften von Klimaschutzpfaden zur Treibhausgasneutralit{\"a}t 2045 und relevante Unsicherheiten}, publisher = {Kopernikus-Projekte}, address = {Potsdam}, pages = {54 S.}, abstract = {Im Rahmen der vier Kopernikus-Projekte - Ariadne, ENSURE, P2X und SynErgie - wird die Transformation des deutschen Energiesystems hin zur Klimaneutralit{\"a}t analysiert. Im vorliegenden Bericht werden hierbei robuste Kernaussagen und relevante Unsicherheiten derjenigen Szenarien der Kopernikus-Schwesterprojekte dargestellt, die zur Zielsetzung die Klimaneutralit{\"a}t 2045 haben. Hierbei liegt der Fokus auf Indikatoren, die eine besonders hohe klimapolitische Relevanz haben.}, language = {de} } @inproceedings{SchweibererRauchBrueckl, author = {Schweiberer, Philipp and Rauch, Johannes and Br{\"u}ckl, Oliver}, title = {Control strategy for industrial reactive power sources depending on a specified reactive power setpoint value}, series = {ETG Kongress 2023: Die Energiewende beschleunigen, 25.-26. Mai 2023, Kassel, Germany}, booktitle = {ETG Kongress 2023: Die Energiewende beschleunigen, 25.-26. Mai 2023, Kassel, Germany}, publisher = {VDE VERLAG}, address = {Berlin}, organization = {Energietechnische Gesellschaft }, isbn = {978-3-8007-6108-1}, pages = {553 -- 558}, abstract = {Industrial plants can provide reactive power (Q) for system- and grid-serving behavior, for which a functioning reactive power management system is essential. To make reactive power retrieval as efficient and safe as possible, the selection of reactive power sources to meet the Q-demand must consider their sensitivities and the restrictions of the industrial grid, such as operating equipment utilization or voltage limits. On this basis, a concept for a sensitivity-based control strategy that manages the reactive power retrieval of multiple reactive power sources depending on a predefined reactive power demand value is proposed. Based on the simulation of an industrial plant in the medium-voltage grid, which can provide reactive power in the form of industrial compensation systems (ICS) and generators, the operation of the algorithm is shown.}, language = {en} } @techreport{AndratschkeCeulloDawoudetal., author = {Andratschke, Christin and Ceullo, Laura and Dawoud, Belal and Draeger, Susan and Gerdes, Thorsten and Giebisch, Matthias and Grießhammer, Peter and Haas, Katharina and Haug, Sonja and Helling, Dominik and Kominis, Lena and Lang, Christian and Malz, Sebastian and Melzl, Johannes and Michlbauer, David and M{\"u}hlberger, Thomas and Nagl, Klaus and Preis, Michael and Rechenauer, Christian and Riederer, Michael and R{\"u}ckerl, Alexander and Saller, Tobias and Schnabl, Andreas and Stadler, Michael and Steffens, Oliver and Steininger, Peter and Stelzl, Andr{\´e} and Toutouly, Lovis and Trauner, Matthias and Vetter, Miriam and Walbrunn, Johannes and Weber, Karsten and Zielbauer, Lukas}, title = {MAGGIE: Energetische Modernisierung des genossenschaftlichen Wohnquartiers Margaretenau in Regensburg}, editor = {Steffens, Oliver}, address = {Regensburg}, isbn = {978-3-96256-100-0}, doi = {10.35096/othr/pub-5335}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-53354}, pages = {XVIII, 462 S.}, abstract = {Im Projekt MAGGIE wurden f{\"u}r das genossenschaftliche historische Stadtquartier „Margaretenau" in Regensburg Musterl{\"o}sungen f{\"u}r energieoptimiertes Wohnen mit innovativen Wandaufbauten aus solaraktiven Baukonstruktionen und einer vorhersagebasierten Versorgungstechnologie erforscht. Dazu wurde ein bestehendes Wohngeb{\"a}ude als Demonstrations- und Versuchsobjekt mit einem neuartigen, besonders effizienten Hybridsystem aus W{\"a}rmepumpentechnologie und Kraft- W{\"a}rme-Kopplung ausgestattet und untersucht, erg{\"a}nzt durch eine dynamische W{\"a}rmelogistik zur Verringerung von Verteilungsverlusten. Das System wurde durch ein neu entwickeltes, allgemein einsetzbares Planungs-, Optimierungs- und Steuerungstool ausgelegt und im Betrieb geregelt. Die in Echtzeit laufende Nachoptimierung des Systems w{\"a}hrend des Betriebs greift dabei auf reale Monitoringdaten zu. Die Einbindung von Nutzerbedarfsprofilen, Stromb{\"o}rse und Wetterdaten in die Steuerung gestattet einen dynamischen und perspektivischen Anlagenbetrieb zur Maximierung der Solar- und Umweltw{\"a}rme-Anteile der Energieversorgung und leistet damit einen wirksamen Beitrag zu einem emissionsarmen, klimafreundlichen Geb{\"a}udebetrieb. F{\"u}r die denkmalgerechte Modernisierung der historischen Fassaden wurde ein solaraktives und solaradaptives Außenputzsystem entwickelt und in der Realit{\"a}t getestet. Am Bestandsgeb{\"a}ude kam anstelle eines W{\"a}rmed{\"a}mmverbundsystems ein innovativer D{\"a}mmputz mit Mikrohohlglaskugeln zum Einsatz. Die Skalierbarkeit erlaubt eine abschnittsweise Modernisierung des gesamten Ensembles {\"u}ber mehrere Jahre. Durch die hohe Energieeffizienz wird die Warmmiete f{\"u}r die Bewohner der genossenschaftlichen Siedlung durch die Modernisierungsmaßnahmen nicht erh{\"o}ht, so dass auch nach der Modernisierung ein bezahlbares Wohnen sichergestellt wird.}, subject = {Altbaumodernisierung}, language = {de} } @inproceedings{Haumer, author = {Haumer, Anton}, title = {Modeling and Control Design of an Educational Magnetic Levitation System}, series = {Proceedings of the 15th International Modelica Conference 2023, Aachen, October 9-11}, booktitle = {Proceedings of the 15th International Modelica Conference 2023, Aachen, October 9-11}, publisher = {Link{\"o}ping University Electronic Press}, issn = {1650-3686}, doi = {10.3384/ecp204763}, abstract = {A magnetic levitation system is a perfect educational example of a nonlinear unstable system. Only with suitable control, a small permanent magnet can be held floating stable below a coil. After modeling and simulation of the system, control of the system can be developed. At the end, the control algorithm can be coded on a microcontroller, connected to a pilot plant.}, language = {en} } @article{SelmairMaurerLaietal., author = {Selmair, Maximilian and Maurer, Tobias and Lai, Chun-Han and Grant, David}, title = {Enhancing the efficiency of charging \& parking processes for Autonomous Mobile Robot fleets}, series = {Journal of Power Sources}, volume = {521}, journal = {Journal of Power Sources}, number = {3}, publisher = {Elsevier}, doi = {10.1016/j.jpowsour.2021.230894}, abstract = {The allocation of tasks to Autonomous Mobile Robots in a production setting in combination with the most efficient parking and charging processes are the focus of this paper. This study presents a simulative evaluation of the theoretical allocation methods developed in Selmair and Maurer (2020) combined with either hard or dynamic availability rules to ascertain the most efficient parameters of an Autonomous Mobile Robot System. In order to quantify this efficiency, the following Key Performance Indicator (KPI) were considered: number of delayed orders, driven fleet metres and the percentage of available Autonomous Mobile Robot as determined by their state of charge. Additionally, as an alternative energy source, a fast-charging battery developed by Battery Streak Inc. was included in this study. The results show that, in comparison to a conventional and commonly used trivial strategy, our developed strategies provide superior results in terms of the relevant KPI.}, language = {en} } @article{WalterSchwanzerSteineretal., author = {Walter, Stefanie and Schwanzer, Peter and Steiner, Carsten and Hagen, Gunter and Rabl, Hans-Peter and Dietrich, Markus and Moos, Ralf}, title = {Mixing Rules for an Exact Determination of the Dielectric Properties of Engine Soot Using the Microwave Cavity Perturbation Method and Its Application in Gasoline Particulate Filters}, series = {Sensors}, volume = {22}, journal = {Sensors}, number = {9}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/s22093311}, pages = {1 -- 17}, abstract = {In recent years, particulate filters have become mandatory in almost all gasoline-powered vehicles to comply with emission standards regarding particulate number. In contrast to diesel applications, monitoring gasoline particulate filters (GPFs) by differential pressure sensors is challenging due to lower soot masses to be deposited in the GPFs. A different approach to determine the soot loading of GPFs is a radio frequency-based sensor (RF sensor). To facilitate sensor development, in previous work, a simulation model was created to determine the RF signal at arbitrary engine operating points. To ensure accuracy, the exact dielectric properties of the soot need to be known. This work has shown how small samples of soot-loaded filter are sufficient to determine the dielectric properties of soot itself using the microwave cavity perturbation method. For this purpose, mixing rules were determined through simulation and measurement, allowing the air and substrate fraction of the sample to be considered. Due to the different geometry of filter substrates compared to crushed soot samples, a different mixing rule had to be derived to calculate the effective filter properties required for the simulation model. The accuracy of the determined mixing rules and the underlying simulation model could be verified by comparative measurements on an engine test bench.}, language = {en} } @article{MikhaeilGadererDawoud, author = {Mikhaeil, Makram and Gaderer, Matthias and Dawoud, Belal}, title = {Experimental Investigation of the Adsorption and Desorption Kinetics on an Open-Structured Asymmetric Plate Heat Exchanger; Matching Between Small-Scale and Full-Scale Results}, series = {Frontiers in Energy Research}, volume = {10}, journal = {Frontiers in Energy Research}, publisher = {Frontiers}, doi = {10.3389/fenrg.2022.818486}, pages = {1 -- 15}, abstract = {This paper introduces the results of an experimental study on the adsorption and desorption kinetics of a commercially available, open-structured asymmetric plate heat exchanger adapted to act as an adsorber/desorber for the application in adsorption heat transformation processes. In addition, a volumetric large temperature jump (V-LTJ) kinetic setup was applied to measure the adsorption and desorption kinetics of a small-scale adsorbent sample prepared dedicatedly to be representative for the adsorbent domain inside the investigated adsorber plate heat exchanger (APHE). All kinetic results of the small-scale adsorbent sample and the APHE were fitted into exponential forms with a single characteristic time constant (τ) with a coefficient of determination (R2) better than 0.9531. A very good matching between the small-scale and full-scale adsorption kinetic measurements was obtained, with an average relative deviation of 12.3\% in the obtained τ-values. In addition, the kinetic data of the small-scale adsorbent sample were utilized for estimating the expected specific instantaneous and moving average powers of the evaporator/condenser heat exchanger. The average relative deviation (ARD) between the moving average specific evaporator powers obtained from the small-scale and the full-scale measurements amounts between 5.4 and 15.1\%.}, language = {en} } @unpublished{GaertnerMarxSchubachGadereretal., author = {G{\"a}rtner, Sebastian and Marx-Schubach, Thomas and Gaderer, Matthias and Schmitz, Gerhard and Sterner, Michael}, title = {Introduction of an Innovative Energy Concept for low Emission Glass Melting based on Carbon Capture and Usage}, doi = {10.31224/2642}, abstract = {Due to the very high fossil energy demand, the glass industry is looking for innovative approaches for the reduction of CO2 emissions and the integration of renewable energy sources. In this paper, we present a novel power-to-gas concept, which has no impact on established melting processes and discuss it for this purpose. A special focus is set on the required CO2 capture from typical flue gases in the glass industry, as this process has not been investigated in detail yet. We used a process simulation approach to investigate post-combustion CO2 capture by absorption processes, followed by a techno-economic evaluation. Our investigations found the designed CO2 capture plant to be approx. 400 times smaller than absorption based CO2 separation processes for conventional power plants. Due to the many options for waste heat utilization, the waste heat required for CO2 desorption can be generated in a particularly efficient and cost-effective way. The resulting CO2 avoidance costs range between 41-42 €/t CO2, depending on waste heat utilization for desorption, and thus offer a cost effective way of CO2 removal from glass industry melting processes. These costs are well below the values of 50-65 €/t CO2 described so far for comparable industrial applications. In addition, we describe optimization options, like solvent and process improvements, to enable further cost reductions. These results motivate further research and development on the overall process presented in this work.}, language = {en} } @article{KaulBoellmannThemaetal., author = {Kaul, Anja and Boellmann, Andrea and Thema, Martin and Kalb, Larissa and Stoeckl, Richard and Huber, Harald and Sterner, Michael and Bellack, Annett}, title = {Combining a robust thermophilic methanogen and packing material with high liquid hold-up to optimize biological methanation in trickle-bed reactors}, series = {Bioresource technology}, volume = {345}, journal = {Bioresource technology}, publisher = {Elsevier}, doi = {10.1016/j.biortech.2021.126524}, abstract = {The hydrogen gas-to-liquid mass transfer is the limiting factor in biological methanation. In trickle-bed reactors, mass transfer can be increased by high flow velocities in the liquid phase, by adding a packing material with high liquid hold-up or by using methanogenic archaea with a high methane productivity. This study developed a polyphasic approach to address all methods at once. Various methanogenic strains and packings were investigated from a microbial and hydrodynamic perspective. Analyzing the ability to produce high-quality methane and to form biofilms, pure cultures of Methanothermobacter performed better than those of the genus Methanothermococcus. Liquid and static hold-up of a packing material and its capability to facilitate attachment was not attributable to a single property. Consequently, it is recommended to carefully match organism and packing for optimized performance of trickle-bed reactors. The ideal combination for the ORBIT system was identified as Methanothermobacter thermoautotrophicus IM5 and DuraTop (R).}, language = {en} } @inproceedings{WagnerAlAbadiBuchner, author = {Wagner, Marcus and Al-Abadi, Ali and Buchner, Stefan}, title = {A Numerical-Based Model to Determine the Resonance of the Steel Cores of Transformers}, series = {ARWtr 2022 proceedings : 2022 7th Advanced Research Workshop on Transformers (ARWtr), October (23)24-26, 2022, Baiona, Spain}, booktitle = {ARWtr 2022 proceedings : 2022 7th Advanced Research Workshop on Transformers (ARWtr), October (23)24-26, 2022, Baiona, Spain}, editor = {L{\´o}pez-Fern{\´a}ndez, Xose M.,}, publisher = {IEEE}, isbn = {978-84-09-45157-9}, doi = {https://doi.org/10.23919/ARWtr54586.2022.9959938}, pages = {36 -- 41}, abstract = {The laminated steel core of transformers is one of the main sources of the generated sound, as it is excited by different electromagnetic effects during its normal operation. If the core is excited in its eigenfrequencies, the sound generated by a transformer will increase significantly. Therefore, knowledge of the core's eigenmodes and -frequencies in an early design stage can decrease expenses by avoiding costly modifications that might be required to avoid the sound levels exceeding the specified values after the final factory acceptance test. The current study focuses on developing a core resonance model to determine the eigenmodes and -frequencies of a transformer core. The core's geometry was simplified to a connected-beam structure and a numerical-based approach was applied. The accuracy of the developed model was validated against finite element method (FEM), using ANSYS on a reference core model.}, language = {en} } @inproceedings{WagnerLehrerFrankeetal., author = {Wagner, Marcus and Lehrer, Tobias and Franke, Markus and Al-Abadi, Ali and Gamil, Ahmed}, title = {A Tank Resonance Model for Power Transformers}, series = {ARWtr 2022 proceedings, 2022 7th Advanced Research Workshop on Transformers (ARWtr): October (23)24-26, 2022, Baiona, Spain}, booktitle = {ARWtr 2022 proceedings, 2022 7th Advanced Research Workshop on Transformers (ARWtr): October (23)24-26, 2022, Baiona, Spain}, publisher = {IEEE}, organization = {Institute of Electrical and Electronics Engineers (IEEE)}, doi = {10.23919/ARWtr54586.2022.9959917}, pages = {7 -- 12}, abstract = {During the factory acceptance test, the sound levels are measured. If the measured sound levels exceed pre-specified values, modifications on the transformer's active part and/or tank need to be conducted. Tank resonance, if occurs, at twice main power frequency and its higher harmonics is one of the main reasons of amplifying the generated sound levels. Therefore, it is preferable to know already in the design stage about the occurrence of the tank resonance and propose reliable tank solutions. The current study presents a newly developed model for calculating the mode shapes and its corresponding eigenfrequencies of the tank.}, language = {en} } @inproceedings{RauchBruecklEngel, author = {Rauch, Johannes and Br{\"u}ckl, Oliver and Engel, Bernd}, title = {Analysis and optimization of the steady state voltage deviation demand for reactive power planning using installed reactive power sources}, series = {NEIS 2022; Conference on Sustainable Energy Supply and Energy Storage Systems, 26-27 September 2022, Hamburg}, booktitle = {NEIS 2022; Conference on Sustainable Energy Supply and Energy Storage Systems, 26-27 September 2022, Hamburg}, editor = {Schulz, Detlef}, publisher = {VDE-Verlag}, address = {Berlin}, isbn = {978-3-8007-5983-5}, issn = {2510-6902}, pages = {175 -- 182}, abstract = {The provision of reactive power is one option for maintaining the grid voltage, that is defined as an ancillary service in Germany. This paper presents an approach for determining deficient voltage deviation demands within an electrical grid for long term reactive power planning investigations. In contrast to previous approaches, which evaluate the Q-behavior of extended ward elements or grid assets, voltage deviations are analyzed bus-specifically. So further reactive power planning investigations are able to scale and optimize additional reactive power sources directly on planning voltage limits using load flow sensitivity techniques. The focus lies on the analysis of the steady state demand at base case conditions. Therefore, a grid planning process is conceptualized. An optimal power flow algorithm based on Differential Evolution is used for an optimal reactive power dispatch of installed reactive power sources, e. g. reactive power compensation systems or (renewable) energy sources to minimize the total voltage deviation according to voltage limits of Transmission System Operators planning principles. Methodological and processuals specifications as well as an application use case with an exemplary transmission system are presented in this paper.}, language = {en} } @inproceedings{SchweibererRauchBrueckl, author = {Schweiberer, Philipp and Rauch, Johannes and Br{\"u}ckl, Oliver}, title = {Long-term analysis of industrial reactive power potentials with consideration of plant-internal grid restrictions using the example of an industrial plant in a distribution grid}, series = {NEIS 2022; Conference on Sustainable Energy Supply and Energy Storage Systems, 26-27 September 2022, Hamburg}, booktitle = {NEIS 2022; Conference on Sustainable Energy Supply and Energy Storage Systems, 26-27 September 2022, Hamburg}, editor = {Schulz, Detlef}, publisher = {VDE-Verlag}, address = {Berlin}, isbn = {978-3-8007-5983-5}, issn = {2510-6902}, pages = {51 -- 56}, abstract = {Since conventional generation plants provide a considerable share of reactive power but are gradually being shut down due to energy transition, leading to power deficits at the transmission grid level, new concepts for the supply of reactive power must be developed. As one possibility for the latter, industrial plants in the distribution grid are considered suitable, as their reactive power potentials can contribute to voltage maintenance and thus to a grid- or system-serving behavior. In this paper, the determination of reactive power potentials provided by industrial compensation systems (ICS) is presented. An industrial plant in the medium voltage grid, with three installed ICSs, is investigated. The potentials are determined and described based on their time characteristics, which provide information about the occurrence and distribution of inductive and capacitive potentials. A grid simulation of the investigated industrial grid is used to analyze the effects of retrieving the reactive power potentials regarding equipment utilizations and voltage limits.}, language = {en} } @misc{ReindlErikssonNiemetzetal., author = {Reindl, Andrea and Eriksson, Lars and Niemetz, Michael and Sangyoung, Park and Meier, Hans}, title = {Control Concepts for a Decentralized Battery Management System Decentralized Battery Management System Global Control Level}, series = {16th International Renewable Energy Storage Conference (IRES2022), 20 to 22 September 2022, D{\"u}sseldorf}, journal = {16th International Renewable Energy Storage Conference (IRES2022), 20 to 22 September 2022, D{\"u}sseldorf}, publisher = {Eurosolar}, language = {en} } @inproceedings{KoernerReindlMeieretal., author = {K{\"o}rner, Patrick and Reindl, Andrea and Meier, Hans and Niemetz, Michael}, title = {A Theoretical Comparison of Different Virtual Synchronous Generator Implementations on Inverters}, series = {2022 24th European Conference on Power Electronics and Applications (EPE'22 ECCE Europe): 05-09 September 2022, Hannover, Germany}, booktitle = {2022 24th European Conference on Power Electronics and Applications (EPE'22 ECCE Europe): 05-09 September 2022, Hannover, Germany}, publisher = {IEEE}, pages = {9}, abstract = {The goal to overcome the global climate crisis leads to a rising demand for the usage of Renewable Energy Sources (RES). Decentralized control strategies are needed to allow the integration of RES into the grid. The Virtual Synchronous Generator (VSG) is proposed as a method to add virtual inertia to the grid by emulating the rotating mass of a Synchronous Generator (SG) on the control algorithm of an inverter. This paper presents the VSG control structure as well as the mathematical description in a unified form. Due to the fact that classical droop control can be seen as a special form of the VSG, their correlation is highlighted by evaluating the steady state output characteristics of the inverter. Furthermore, a theoretical comparison between different VSG topologies, including the VISMA-Method 2 and the synchronverter, is given. In order to achieve better voltage stability, principles to add virtual impedance to the inverter's output are described.}, language = {en} } @article{SchaechingerBruecklBeckeretal., author = {Sch{\"a}chinger, J. and Br{\"u}ckl, Oliver and Becker, Mark and Lechner, Raphael}, title = {Results of the Research Project Optibiosy: Biogas plants as stabilizers of the power system?}, series = {BWK ENERGIE}, volume = {74}, journal = {BWK ENERGIE}, number = {11-12}, publisher = {VDI-Verlag}, address = {D{\"u}sseldorf}, issn = {1436-4883}, pages = {34 -- 39}, language = {en} } @article{GamischHuberGadereretal., author = {Gamisch, Bernd and Huber, Lea and Gaderer, Matthias and Dawoud, Belal}, title = {On the Kinetic Mechanisms of the Reduction and Oxidation Reactions of Iron Oxide/Iron Pellets for a Hydrogen Storage Process}, series = {Energies}, volume = {15}, journal = {Energies}, number = {21}, publisher = {MDPI}, doi = {10.3390/en15218322}, abstract = {This work aims at investigating the kinetic mechanisms of the reduction/oxidation (redox) reactions of iron oxide/iron pellets under different operating conditions. The reaction principle is the basis of a thermochemical hydrogen storage system. To simulate the charging phase, a single pellet consisting of iron oxide (90\% Fe2O3, 10\% stabilising cement) is reduced with different hydrogen (H2) concentrations at temperatures between 600 and 800 °C. The discharge phase is initiated by the oxidation of the previously reduced pellet by water vapour (H2O) at different concentrations in the same temperature range. In both reactions, nitrogen (N2) is used as a carrier gas. The redox reactions have been experimentally measured in a thermogravimetric analyser (TGA) at a flow rate of 250 mL/min. An extensive literature review has been conducted on the existing reactions' kinetic mechanisms along with their applicability to describe the obtained results. It turned out that the measured kinetic results can be excellently described with the so-called shrinking core model. Using the geometrical contracting sphere reaction mechanism model, the concentration- and temperature-dependent reduction and oxidation rates can be reproduced with a maximum deviation of less than 5\%. In contrast to the reduction process, the temperature has a smaller effect on the oxidation reaction kinetics, which is attributed to 71\% less activation energy (Ea,Re=56.9 kJ/mol versus Ea,Ox=16.0 kJ/mol). The concentration of the reacting gas showed, however, an opposite trend: namely, to have an almost twofold impact on the oxidation reaction rate constant compared to the reduction rate constant.}, language = {en} } @inproceedings{ArrietaCastroRill, author = {Arrieta Castro, Abel and Rill, Georg}, title = {Kinematic Versus Elasto-Kinematic Model of a Twistbeam Suspension}, series = {Advances in Dynamics of Vehicles on Roads and Tracks II, proceedings of the 27th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2021): August 17-19, 2021, Saint Petersburg, Russia}, booktitle = {Advances in Dynamics of Vehicles on Roads and Tracks II, proceedings of the 27th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2021): August 17-19, 2021, Saint Petersburg, Russia}, editor = {Orlova, Anna and Cole, David}, publisher = {Springer Nature}, doi = {10.1007/978-3-031-07305-2_59}, pages = {505 -- 605}, abstract = {The Twistbeam axle suspension is a cheap and robust layout for rear axles at front wheel driven midsize cars. Appropriate models have to take the elastic deformation of the torsion beam into account. A Finite Element approach requires detailed informations of the material properties and the shape which are usually only available in the final production stage. This paper presents a lumped mass model which can easily be integrated into a multibody vehicle model and can be used in the early stage of development. An approximation by the design kinematics further reduces the complexity of the model and considers only the kinematic properties of the Twistbeam suspension. Simulations using a nonlinear and three-dimensional vehicle model with different maneuvers, such as steady-state cornering, step steer input, and driving straight ahead on random road, demonstrate the performance and, in particular, the difference of the presented Twistbeam suspension models.}, language = {en} } @inproceedings{BuenteRillRuggaberetal., author = {B{\"u}nte, Tilman and Rill, Georg and Ruggaber, Julian and Tobol{\´a}ř, Jakub}, title = {Modelling and Validation of the TMeasy Tyre Model for Extreme Parking Manoeuvres}, series = {Advances in Dynamics of Vehicles on Roads and Tracks II, Proceedings of the 27th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2021): August 17-19, 2021, Saint Petersburg, Russia}, booktitle = {Advances in Dynamics of Vehicles on Roads and Tracks II, Proceedings of the 27th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2021): August 17-19, 2021, Saint Petersburg, Russia}, editor = {Orlova, Anna and Cole, David}, publisher = {Springer}, address = {Cham}, isbn = {978-3-031-07305-2}, doi = {10.1007/978-3-031-07305-2_94}, pages = {1015 -- 1025}, abstract = {The TMeasy is a tyre model suitable for vehicle handling analyses and enables easy parametrisation. Recently, a convenient interface to Modelica was implemented by DLR to support the TMeasy also for vehicle modelling in multi-physical domains. This paper focuses especially on the particular problem of reliable reproduction of the tyre's bore torque which occurs during parking manoeuvres. It outlines the theory behind it, discusses the Modelica interface implementation, and presents the results of parameter identification which were achieved based on real experiments with DLR's research platform ROboMObil.}, language = {en} } @inproceedings{Rill, author = {Rill, Georg}, title = {A Three-Dimensional and Nonlinear Virtual Test Car}, series = {ENOC 2022, book of abstracts, 10th European Nonlinear Dynamics Conference: July 17-22, 2022, Lyon, France}, booktitle = {ENOC 2022, book of abstracts, 10th European Nonlinear Dynamics Conference: July 17-22, 2022, Lyon, France}, address = {Lyon}, pages = {49 -- 58}, abstract = {Virtual testing procedures have become a standard in vehicle dynamics. The increasing complexity of driver assistance sys- tems demand for more and more virtual tests, which are supposed to produce reliable results even in the limit range. As a consequence, simplified vehicle models, like the classical bicycle model or 4-wheel vehicle models, have to be replaced by a fully three-dimensional and nonlinear vehicle model, which also encompasses the details of the suspension systems. This paper presents a passenger car model, where the chassis, the four knuckles, and the four wheels are described by rigid bodies, the suspension system is modeled by the generic design kinematics, and the TMeasy tire model provides the tire forces and torques in all driving situations.}, language = {en} } @article{EmbergerAltmannGebhardetal., author = {Emberger, Peter and Altmann, Robert and Gebhard, J{\"u}rgen and Thuneke, Klaus and Winkler, Markus and T{\"o}pfer, Georg and Rabl, Hans-Peter and Remmele, Edgar}, title = {Combustion characteristics of pure rapeseed oil fuel after injection in a constant volume combustion chamber with a non-road mobile machinery engine solenoid injector}, series = {Fuel}, journal = {Fuel}, number = {320}, publisher = {Elsevier}, doi = {10.1016/j.fuel.2022.123979}, abstract = {Pure rapeseed oil fuel (R100) according to standard DIN 51605 is a greenhouse gas saving option for the mobility sector. With its high energy density close to diesel fuel, R100 is suitable to operate non-road mobile machinery with a high power demand and long operating time, where electric drives reach their limits. Advantages are indicated for its use in environmentally sensitive areas like agriculture since R100 is highly biodegradable and non-toxic. However, R100 is characterised by differing physical and chemical properties compared to diesel. The objective of the research is to investigate the differences in the ignition and combustion behaviour of R100 compared to diesel fuel (DF). For this purpose, a constant volume combustion chamber is used, which is equipped with a modern solenoid injector for engines of non-road mobile machinery. The researched injector shows a different hydraulic behaviour when using R100 compared to DF in that the injected fuel mass is lower with R100 than with DF. In combination with the 14 \% by mass lower calorific value, less energy output is determined with R100. When varying the injection pressure, the impact on the ignition delay and combustion behaviour is much higher for R100 than for DF. Specifically, an increase of the injection pressure supports mixture preparation and thus partially compensates the differing physical properties of R100. The results of ignition delay measurements and net heat release analysis are as follows: At low load conditions with low injection pressure as well as a low combustion chamber temperature and pressure, R100 ignites later and shows a further delayed combustion compared to diesel. The opposite is observed for medium and high load conditions, where R100 ignites faster and without delayed combustion in comparison to DF. Thus, an adjustment of the heat release of R100 at the same level as for DF is possible by modifying the injection strategy. The research shows that for an optimised combustion of R100 the injection settings must be adjusted for every operation point separately. The results indicate how the injection parameters should be adjusted for different load conditions to realise a high-quality engine calibration for R100.}, language = {en} } @inproceedings{LaloSailerMottoketal., author = {Lalo, Erjola and Sailer, Andreas and Mottok, J{\"u}rgen and Siemers, Christian}, title = {Overhead-Aware Schedule Synthesis for Logical Execution Time (LET) in Automotive Systems}, series = {2022 IEEE 35th International System-on-Chip Conference (SOCC): 05-08 September 2022, Belfast, United Kingdom}, booktitle = {2022 IEEE 35th International System-on-Chip Conference (SOCC): 05-08 September 2022, Belfast, United Kingdom}, publisher = {IEEE}, isbn = {978-1-6654-5985-3}, doi = {10.1109/SOCC56010.2022.9908103}, pages = {1 -- 6}, abstract = {The Logical Execution Time (LET) has recently been integrated in multi-core automotive systems to ensure timing and dataflow determinism. Although buffering mechanisms are introduced to incorporate LET semantics, they do not guarantee that tasks are executed within their LET frames. In fact, LET and buffering semantics are violated if scheduling is not designed to execute all tasks within their LET frames and in a specific order. In this paper, we describe a scheduling synthesis technique for Fixed-Priority Scheduling (FPS) to achieve resource-efficient execution of LET systems. The proposed approach considers LET semantics, scheduling overheads, and delays caused by operating system operations and provides the possibility to optimize the schedule with respect to aspects like scheduling overheads. Our performance and feasibility evaluation shows that the proposed algorithm provides results in a reasonable amount of time for models of complex industrial applications. Thus, the integration of the proposed algorithm into an automated process is of high benefit to accelerate the development of vehicle applications.}, language = {en} } @incollection{BauerGawlikSterneretal., author = {Bauer, Franz and Gawlik, Julia and Sterner, Michael and Hamacher, Thomas}, title = {{\"U}bergreifende Energiesystemmodellierung}, series = {Optionen f{\"u}r ein nachhaltiges Energiesystem mit Power-to-X-Technologien: Transformation - Anwendungen - Potentiale. 4. Roadmap des Kopernikus-Projektes P2X, Phase II}, booktitle = {Optionen f{\"u}r ein nachhaltiges Energiesystem mit Power-to-X-Technologien: Transformation - Anwendungen - Potentiale. 4. Roadmap des Kopernikus-Projektes P2X, Phase II}, editor = {Ausfelder, Florian and Du Tran, Dinh}, publisher = {DECHEMA Gesellschaft f{\"u}r Chemische Technik und Biotechnologie e.V.}, address = {Frankfurt a.M.}, isbn = {978-3-89746-238-0}, pages = {17 -- 35}, language = {de} } @misc{WalterSchwanzerHagenetal., author = {Walter, Stefanie and Schwanzer, Peter and Hagen, Gunter and Rabl, Hans-Peter and Dietrich, Markus and Moos, Ralf}, title = {Combined Ash and Soot Monitoring in Gasoline Particulate Filters with a Radio-Frequency-Based Sensor}, series = {SAE World Congress Experience, April 5-7, 2022, Detroit, Michigan, USA}, journal = {SAE World Congress Experience, April 5-7, 2022, Detroit, Michigan, USA}, abstract = {In recent years, it turned out that primarily the number of ultrafine particles and not their mass is relevant in terms of harmful health effects. Therefore, exhaust emission standards are constantly being tightened with regard to the particulate number. To meet the emission limits, particulate filters have become necessary for gasoline engines. Similar to diesel applications, gasoline particulate filters (GPFs) can be monitored via differential pressure measurement or via a radio-frequency approach (RF-sensor). The latter is based on the influence of the soot conductivity on the electromagnetic field. To control the GPF, ash detection is of crucial importance besides the soot load monitoring. With the differential pressure system, this is only possible with high uncertainties due to the low pressure increase caused by ash. The RF-sensor, however, has already demonstrated its potential for ash detection in diesel applications. In order to verify the applicability of the system for GPFs, filters were loaded via a method for fast ash loading. Thereby, it was shown that by evaluating resonant modes - especially the resonant frequency - the ash loading can easily be measured as long as the filter is soot-unloaded. In contrast, soot loading can be determined independently from this by considering a frequency-averaged transmission signal between the antennas of the RF-sensor. Using a setup for radio-frequency material characterization, the dielectric parameters of the generated ash were also measured. In comparison with the properties of the synthetic soot PrintexU, ash showed significantly lower dielectric losses. Thus, the evaluation of the loss-dependent quality factor, which is only possible at low soot loadings, allows a precise conclusion whether the filter is completely soot-free. Furthermore, using synthetic soot loading, it could be shown that soot detection via the averaged transmission signal is not affected by ash. In summary, it could be shown that with the RF-sensor, ash and soot can be simultaneously detected.}, language = {en} } @inproceedings{RiegerOetjenvandeParetal., author = {Rieger, Anna and Oetjen, Arne and van de Par, Steven and Rabl, Hans-Peter}, title = {Einfluss der Dissonanz auf die Wahrnehmung der Ger{\"a}uschqualit{\"a}t}, series = {Fortschritte der Akustik DAGA 2022: 48. Jahrestagung f{\"u}r Akustik, 21. - 24. M{\"a}rz 2022, Stuttgart und Online}, volume = {48}, booktitle = {Fortschritte der Akustik DAGA 2022: 48. Jahrestagung f{\"u}r Akustik, 21. - 24. M{\"a}rz 2022, Stuttgart und Online}, publisher = {Deutsche Gesellschaft f{\"u}r Akustik e.V.}, address = {Stuttgart}, language = {de} } @article{UhlarHeyderKoenig, author = {Uhlar, Stefan and Heyder, Florian and Koenig, Thomas}, title = {Assessment of two physical tyre models in relation to their NVH performance up to 300 Hz}, series = {Vehicle system dynamics}, volume = {59}, journal = {Vehicle system dynamics}, number = {3}, publisher = {Taylor\&Francis}, doi = {10.1080/00423114.2019.1681475}, pages = {331 -- 351}, abstract = {The prediction of structure-borne noise using numerical methods has a crucial influence during the development process of modern passenger cars. In order to minimise the dynamic forces from the chassis transferred to the body structure, multibody simulation (MBS) can be used. The link between the road surface and the chassis is established by the tyre and its own structural dynamic characteristics. Therefore, it is substantial and the main goal of the present paper to investigate the Noise, Vibration and Harshness (NVH) performance of two commercial physical tyre models available and commonly used in the market. The intention is to point out what kind of results (up-to-date) a user of these structural dynamic tyre models, namely FTire and CDtire/3D, will get with a focus on NVH. The authors strictly follow the established process of how to obtain the fitted tyre property files, as any other user of FTire and CDTire currently does. This process includes a measurement campaign of the real tyre and a subsequent fitting of the tyre property file. The fitting in this case is provided by the tyre model developers themselves, namely cosin and Fraunhofer ITWM. The tyre models are then integrated into the MBS software MSC.Adams where their performance will be assessed based on measured wheel-hub forces in the time and frequency domain up to 300 Hz.}, language = {en} } @incollection{MuehlbauerRablRottengruber, author = {M{\"u}hlbauer, Christian and Rabl, Hans-Peter and Rottengruber, Hermann}, title = {Acoustic Optimization of Mechatronic Direct Injection Systems and Analysis of the Effects on Robustness in System Operation}, series = {SAE International Journal of Advances and Current Practices in Mobility}, volume = {4}, booktitle = {SAE International Journal of Advances and Current Practices in Mobility}, number = {1}, publisher = {SAE International, Warrendale, PA, United States}, issn = {2641-9645}, doi = {10.4271/2021-01-0671}, pages = {68 -- 77}, abstract = {The tightening of the emission legislation and political and social demands for sustainable mobility are forcing the automotive industry to develop complex, high precision mechatronic drive systems. The increasing precision of mechatronic components generally leads to an increase in structural excitation and thus to a rise in noise. The so-called ticking of the fuel injection system has a rather low sound pressure level compared to the residual engine noise. Nevertheless, the impulsive and high frequency noise character leads to a decline concerning the perception of comfort and sound quality. In order to identify the sound quality of fuel injection systems as a frontloading measure, a system test bench has been developed which represents the structure-borne and airborne sound radiation of the stand-alone injection system in a close to series configuration. In this paper, measures for the acoustic optimization of injection systems and their effects on the robustness of the system are discussed. The focus is on engine idling, since at this operating point the ticking of the injectors and high-pressure pump can be perceived most clearly due to the low masking effects of other noise sources. For this purpose, the injection parameters were measured during full engine operation and transferred to the system test bench. By using a special development control unit, it was possible to modify the parameters, quantify their influence on the acoustic behavior and, based on this, define NVH optimized control strategies. For the robustness evaluation of the NVH optimized control strategies, key functions of the injection system were analyzed under varying boundary conditions in system operation on an injection rate test bench.}, language = {en} } @article{KurzweilScheuerpflug, author = {Kurzweil, Peter and Scheuerpflug, Wolfgang}, title = {State-of-charge monitoring and battery diagnosis of different lithium ion chemistries using impedance spectroscopy}, series = {Batteries}, volume = {7}, journal = {Batteries}, number = {1}, doi = {10.3390/batteries7010017}, pages = {16}, abstract = {For lithium iron phosphate batteries (LFP) in aerospace applications, impedance spectroscopy is applicable in the flat region of the voltage-charge curve. The frequency-dependent pseudocapacitance at 0.15 Hz is presented as useful state-of-charge (SOC) and state-of-health (SOH) indicator. For the same battery type, the prediction error of pseudocapacitance is better than 1\% for a quadratic calibration curve, and less than 36\% for a linear model. An approximately linear correlation between pseudocapacitance and Ah battery capacity is observed as long as overcharge and deep discharge are avoided. We verify the impedance method in comparison to the classical constant-current discharge measurements. In the case of five examined lithium-ion chemistries, the linear trend of impedance and SOC is lost if the slope of the discharge voltage curve versus SOC changes. With nickel manganese cobalt (NMC), high impedance modulus correlates with high SOC above 70\%.}, language = {en} } @misc{AltmannGadererRabl, author = {Altmann, Robert and Gaderer, Matthias and Rabl, Hans-Peter}, title = {Pr{\"u}fstandsuntersuchungen an einem DEUTZ NRMM Motor mit Raps{\"o}lkraftstoff und Optimierung des Betriebs- und Emissionsverhaltens durch statistische Versuchsplanung}, series = {18. Internationaler Fachkongress "Kraftstoffe der Zukunft 2021" - digital \& international vernetzt!, online}, journal = {18. Internationaler Fachkongress "Kraftstoffe der Zukunft 2021" - digital \& international vernetzt!, online}, language = {de} } @article{SteiningerGadererDawoud, author = {Steininger, Peter and Gaderer, Matthias and Dawoud, Belal}, title = {Assessment of the Annual Transmission Heat Loss Reduction of a Refurbished Existing Building with an Advanced Solar Selective Thermal Insulation System}, series = {Sustainability}, volume = {13}, journal = {Sustainability}, number = {13}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/su13137336}, pages = {1 -- 19}, abstract = {A numerical parameter sensitivity analysis of the design parameters of the recently published solar selective thermal insulation system (SATIS) has been carried out to enhance its thermal and optical properties. It turned out that the insulation properties of SATIS can be effectively improved by reducing the length of the glass closure element. Increasing the area share of the light conducting elements (LCEs) and decreasing their length-to-diameter (L/D) ratio were identified as key parameters in order to increase the solar gain. Two SATIS variants were compared with the same wall insulation without SATIS in a yearly energetic performance assessment. The SATIS variant with 10 mm length of the closure element, 44.2\% area share of LCE, as well as front and rear diameters of 12 mm/9 mm shows an 11.8\% lower transmission heat loss over the heating period than the wall insulation without SATIS. A new methodology was developed to enable the implementation of the computed solar gains of SATIS in 1D simulation tools. The result is a radiant heat flow map for integration as a heat source in 1D simulation models. A comparison between the 1D and 3D models of the inside wall heat fluxes showed an integral yearly agreement of 98\%.}, language = {en} } @article{SavelievFetisovChashinetal., author = {Saveliev, Dmitry and Fetisov, Leonid Y. and Chashin, Dmitri V. and Fetisov, Yuri K. and Khon, Anastasia and Shamonin (Chamonine), Mikhail}, title = {Effects of ferromagnetic-material thickness on magnetoelectric voltage transformation in a multiferroic heterostructure}, series = {Smart Materials and Structures}, volume = {30}, journal = {Smart Materials and Structures}, number = {6}, publisher = {IOP PUBLISHING}, doi = {10.1088/1361-665X/abf6c0}, abstract = {A magnetoelectric (ME) voltage transformer is fabricated on the basis of a ferromagnetic (FM)-piezoelectric (PE) heterostructure comprising two equally thick laminated layers of an amorphous FM alloy and a piezoceramic lead zirconate-titanate layer sandwiched between them. The structure, placed inside an excitation coil, is electrically poled and magnetized in the direction of the long axis. The primary voltage is applied to the coil and the secondary voltage is measured between the electrodes of the PE material. It is shown for the first time that the change in the total thickness of magnetic layers significantly influences the transformer ' s characteristics. At the largest total thickness of FM layers of 138 mu m, the open-circuit voltage transformation ratio K has a maximum value of about 20, and the power transfer efficiency eta at a matched resistive load of about 20 k omega reaches 45\%. The variation of the control magnetic field in the range of 0-21.6 kA m(-1) makes it possible to change the voltage transformation ratio K from zero to the maximum value. A simple model allows one to calculate the dependence of the characteristics of the ME transformer on the frequency of the primary voltage, thickness of the FM layers, control magnetic field, and the load.}, language = {en} } @article{VerezBorriCrespoetal., author = {V{\´e}rez, David and Borri, Emiliano and Crespo, Alicia and Zsembinszki, Gabriel and Dawoud, Belal and Cabeza, Luisa F.}, title = {Experimental Study of a Small-Size Vacuum Insulated Water Tank for Building Applications}, series = {Sustainability}, volume = {13}, journal = {Sustainability}, number = {10}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/su13105329}, pages = {1 -- 11}, abstract = {Insulation of thermal energy storage tanks is fundamental to reduce heat losses and to achieve high energy storage efficiency. Although water tanks were extensively studied in the literature, the enhancement of the insulation quality is often overlooked. The use of vacuum insulation has the potential to significantly reduce heat losses without affecting the dimension of the storage system. This paper shows for the first time the results of the heat losses tests done for a 0.535 m3 water tank for residential building applications built with a double wall vacuum insulation. The different tests show that the rate of heat losses strictly depends on the temperature distribution inside the tank at the beginning of the experiment. Compared to a conventional water tank insulated with conventional materials, the U-value of the lateral surface was reduced by almost three times (from 1.05 W/K·m2 to 0.38 W/K·m2) using vacuum insulation. However, the bottom part, which is usually used to place the support parts and the piping, is the critical design part of those tanks acting as a thermal bridge with the ambient and enhancing heat losses.}, language = {en} } @article{BelyaevaKleppLemmeletal., author = {Belyaeva, Inna A. and Klepp, J{\"u}rgen and Lemmel, Hartmut and Shamonin (Chamonine), Mikhail}, title = {Feasibility of Probing the Filler Restructuring in Magnetoactive Elastomers by Ultra-Small-Angle Neutron Scattering}, series = {Applied Sciences}, volume = {11}, journal = {Applied Sciences}, number = {10}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/app11104470}, pages = {1 -- 9}, abstract = {Ultra-small-angle neutron scattering (USANS) experiments are reported on isotropic magnetoactive elastomer (MAE) samples with different concentrations of micrometer-sized iron particles in the presence of an in-plane magnetic field up to 350 mT. The effect of the magnetic field on the scattering curves is observed in the scattering vector range between 2.5 x 10(-5) and 1.85 x 10(-4) angstrom(-1). It is found that the neutron scattering depends on the magnetization history (hysteresis). The relation of the observed changes to the magnetic-field-induced restructuring of the filler particles is discussed. The perspectives of employing USANS for investigations of the internal microstructure and its changes in magnetic field are considered.}, language = {en} } @article{GamischGadererDawoud, author = {Gamisch, Bernd and Gaderer, Matthias and Dawoud, Belal}, title = {On the Development of Thermochemical Hydrogen Storage: An Experimental Study of the Kinetics of the Redox Reactions under Different Operating Conditions}, series = {Applied Sciences}, volume = {11}, journal = {Applied Sciences}, number = {4}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/app11041623}, pages = {1 -- 15}, abstract = {This work aims at investigating the reduction/oxidation (redox) reaction kinetics on iron oxide pellets under different operating conditions of thermochemical hydrogen storage. In order to reduce the iron oxide pellets (90\% Fe2O3, 10\% stabilizing cement), hydrogen (H2) is applied in different concentrations with nitrogen (N2), as a carrier gas, at temperatures between between 700 ∘C and 900 ∘C, thus simulating the charging phase. The discharge phase is triggered by the flow of a mixture out of steam (H2O) and N2 at different concentrations in the same temperature range, resulting in the oxidizing of the previously reduced pellets. All investigations were carried out in a thermo-gravimetric analyzer (TGA) with a flow rate of 250mL/min. To describe the obtained kinetic results, a simplified analytical model, based on the linear driving force model, was developed. The investigated iron oxide pellets showed a stable redox performance of 23.8\% weight reduction/gain, which corresponds to a volumetric storage density of 2.8kWh/(L bulk), also after the 29 performed redox cycles. Recalling that there is no H2 stored during the storage phase but iron, the introduced hydrogen storage technology is deemed very promising for applications in urban areas as day-night or seasonal storage for green hydrogen.}, language = {en} } @misc{Sterner, author = {Sterner, Michael}, title = {Gas aus einer Gesamtenergieversorgungsperspektive - Warum wir Power-to-X f{\"u}r die Klimaneutralit{\"a}t brauchen}, series = {Kopernikus-Konferenz Projekt "Ensure" (Deutsche Umwelthilfe), 15. April 2021}, journal = {Kopernikus-Konferenz Projekt "Ensure" (Deutsche Umwelthilfe), 15. April 2021}, language = {de} } @unpublished{KaulBoellmannThemaetal., author = {Kaul, Anja and B{\"o}llmann, Andrea and Thema, Martin and Kalb, Larissa and St{\"o}ckl, Richard and Huber, Harald and Sterner, Michael and Bellack, Annett}, title = {Identification of Robust Thermophilic Methanogenic Archaea and Packing Material for High Liquid Hold-Up at Low Volumetric Gas Flow Rates for Use in Trickle-Bed Reactors for Biological Methanation}, series = {SSRN Electronic Journal}, journal = {SSRN Electronic Journal}, doi = {10.2139/ssrn.3940878}, abstract = {he hydrogen gas-to-liquid mass transfer is the limiting factor in biological methanation. In a trickle-bed reactor, mass transfer can be increased by high flow velocities in the liquid phase, by adding a packing material with high liquid hold-up, or by choosing methanogenic archaea with a high methane productivity. This study analyzed various packings and methanogenic strains from a hydrodynamic and microbial perspective. By analyzing twelve pure cultures of thermophilic methanogens for their ability to produce high quality methane and to form biofilms on different packings, strains of Methanothermobacter were found to perform better than thus of the genus Methanothermococcus. Best methane production and adherence was observed on DuraTop®, Bioflow 9, and filter foam. DuraTop® and Bioflow 9 had also a high dynamic liquid hold-up, but the maximum hold-up was determined for expanded clay. The ideal combination for use in the ORBIT-trickle-bed reactor was identified as Methanothermobacter thermoautotrophicus IM5 and DuraTop®.}, language = {en} } @misc{SternerSchumm, author = {Sterner, Michael and Schumm, Leon}, title = {Netzpuffer - Speicher \& Kraftwerke als virtuelle Leitungen f{\"u}r mehr Versorgungssicherheit und EE-Integration in Nord und S{\"u}d}, series = {7. Smart-Grid-Fachtagung WAGO, Hannover, 29. Sept. 2021}, journal = {7. Smart-Grid-Fachtagung WAGO, Hannover, 29. Sept. 2021}, language = {de} } @misc{Sterner, author = {Sterner, Michael}, title = {Gr{\"u}ner Wasserstoff - wo wir ihn brauchen f{\"u}r die Klimaneutralit{\"a}t}, series = {Energiewendeforum Wasserstoff (Gr{\"u}ner Strom Label e. V.), Bonn, 21. September 2021}, journal = {Energiewendeforum Wasserstoff (Gr{\"u}ner Strom Label e. V.), Bonn, 21. September 2021}, language = {de} } @misc{Sterner, author = {Sterner, Michael}, title = {Wie wird Deutschland klimaneutral? Neue L{\"o}sungen f{\"u}r erneuerbare Energieerzeugung}, series = {Jahreskonferenz der Stiftung Nagelschneider zur Erforschung, M{\"u}nchen, 19.11.2021}, journal = {Jahreskonferenz der Stiftung Nagelschneider zur Erforschung, M{\"u}nchen, 19.11.2021}, address = {M{\"u}nchen}, language = {de} } @misc{Sterner, author = {Sterner, Michael}, title = {Power-to-X for Europes Energy Transformation - Booster H2Global}, series = {Hydrogen Online Workshop Conference (Mission Hydrogen), 25.03.2021}, journal = {Hydrogen Online Workshop Conference (Mission Hydrogen), 25.03.2021}, language = {en} } @misc{Sterner, author = {Sterner, Michael}, title = {Technologieausblick Solarstromspeicher}, series = {Innovationsforum Photovoltaik, 18. Oktober 2021, Linz}, journal = {Innovationsforum Photovoltaik, 18. Oktober 2021, Linz}, language = {de} } @misc{Sterner, author = {Sterner, Michael}, title = {Die Grenzen des Wasserstoff-Hypes}, series = {1. Mitteldeutscher Wasserstoffkongress, 2. November 2021, Leuna CCE Kulturhaus}, journal = {1. Mitteldeutscher Wasserstoffkongress, 2. November 2021, Leuna CCE Kulturhaus}, language = {de} } @inproceedings{AltmannGebhardTroegeretal., author = {Altmann, Robert and Gebhard, J{\"u}rgen and Troeger, Adrian and Winkler, Markus and T{\"o}pfer, Georg and Remmele, Edgar and Gaderer, Matthias and Rabl, Hans-Peter}, title = {Engine performance and emission analysis of a NRMM CI engine with common rail injection system operated with diesel fuel and rapeseed oil fuel}, series = {Proceedings of the 6th Commercial Vehicle Technology Symposium 2020/2021}, booktitle = {Proceedings of the 6th Commercial Vehicle Technology Symposium 2020/2021}, editor = {Berns, Karsten and Dressler, Klaus and Kalmar, Ralf and Stephan, Nicole and Teutsch, Roman and Thul, Martin}, publisher = {Springer Vieweg}, address = {Wiesbaden}, isbn = {978-3-658-29716-9}, doi = {10.1007/978-3-658-29717-6_16}, pages = {231 -- 242}, abstract = {The use of alternative fuels in high-power non-road mobile machinery (NRMM) combustion engines is a possible way to substitute fossil fuel. By using pure vegetable oil fuels, like rapeseed oil fuel (DIN 51605), the greenhouse gases can be reduced effectively. Due to the differences in physical and chemical properties, a modification of the engine control unit calibration is necessary to adapt the working process on the fuel. Without modifications, the engine power output with rapeseed oil fuel is lower than with diesel fuel because of the smaller energy content. By adapting the engine settings, like the injection fuel mass, the power loss can be compensated but it accompanies with a higher fuel consumption. The engine emissions at part load conditions show, that there are benefits in particle emissions by using rapeseed oil at similar NOx emissions. Therefore, a design of experiment setup was initiated on a selected engine operation point to determine the effects of further parameters, like rail pressure, manifold pressure and injection pattern, on the process and to see the potential of an optimized calibration.}, language = {en} } @inproceedings{ButtnerAlonsoVillaBohigasBoladerasetal., author = {Buttner, Johannes and Alonso-Villa, Cristina and Bohigas Boladeras, Pere and Kucera, Markus and Waas, Thomas}, title = {The Need for New Software Architectures for Next-generation Vehicle}, series = {Proceedings of the 5th International E-Conference on Advances in Engineering, Technology and Management (ICETM 2021)}, booktitle = {Proceedings of the 5th International E-Conference on Advances in Engineering, Technology and Management (ICETM 2021)}, isbn = {978-1-63248-192-4}, pages = {58 -- 61}, abstract = {Assuming that future connected cars with automated driving functions will require even more computing power and communication bandwidth, the current network infrastructure as well as the existing individualized control units are not a profitable option for such vehicles. In addition, changing user expectations demand flexible architectural patterns and upgradeability of software components without the need to visit the workshop. However, the current statically developed and configured ECU architecture does not offer any practicable possibilities for this. For these reasons, the research for a new dynamic and flexible architecture is necessary. This new type of system architecture is expected to meet future requirements in terms of space, cost, performance, energy efficiency and number of required computing units in the vehicle, which will arise as a result of the implementation/inclusion of new automated driving functionalities, and due to the changes in user expectations. Solutions to this issue can be found in the field of enterprise IT (cluster computing), in which technologies such as Ethernet, container-based virtualization and flexible software architectures have proven themselves to be very efficient for years. Relevant infrastructures, for example from cloud computing providers, have commonly been used in high-performance or high-availability applications. Thus, in the research project A 3F has been investigated which of these concepts and methods can be applied to modern vehicle system architectures. One of the main goals is to assess the synergy potential of the two sectors, information technology and automotive industry, which to date have very different orientations. However, this synergy is expected to grow strongly in the course of the developments mentioned above. In the following pages, the necessary changes related to hardware and software will be discussed briefly und will be compared to concepts and possible solutions from the IT world.}, language = {en} } @inproceedings{MuehlbauerRablRottengruber, author = {M{\"u}hlbauer, Christian and Rabl, Hans-Peter and Rottengruber, Hermann}, title = {Akustische Optimierung von mechatronischen Direkteinspritzsystemen und Analyse der Auswirkungen auf die Robustheit im Systembetrieb}, series = {Motor- und Aggregate-Akustik: 11. Magdeburger Symposium, Tagungsband}, volume = {11}, booktitle = {Motor- und Aggregate-Akustik: 11. Magdeburger Symposium, Tagungsband}, publisher = {Otto-von-Guericke-Universit{\"a}t}, address = {Magdeburg}, doi = {10.25673/36611}, pages = {32 -- 51}, abstract = {The tightening of the emission legislation and political and social demands for sustainable mobility are forcing the automotive industry to develop complex, high precision mechatronic drive systems. The increasing precision of mechatronic components generally leads to an increase in structural excitation and thus to a rise in noise. The socalled ticking of the fuel injection system has a rather low sound pressure level compared to the residual engine noise. Nevertheless, the impulsive and high frequency noise character leads to a decline concerning the perception of comfort and sound quality. In order to identify the sound quality of fuel injection systems as a frontloading measure, a system test bench has been developed which represents the structureborne and airborne sound radiation of the stand-alone injection system in a close to series configuration. In this paper, measures for the acoustic optimization of injection systems and their effects on the robustness of the system are discussed. The focus is on engine idling, since at this operating point the ticking of the injectors and the high-pressure pump can be perceived most clearly due to the low masking effects of other noise sources. For this purpose, the injection parameters were measured during full engine operation and transferred to the system test bench. By using a special development control unit, it was possible to modify the parameters, quantify their influence on the acoustic behavior and, based on this, define NVH optimized control strategies. For the robustness evaluation of the NVH optimized control strategies, key functions of the injection system were analyzed under varying boundary conditions in system operation on an injection rate test bench.}, language = {de} } @inproceedings{SchneiderMuehlbauerSittletal., author = {Schneider, Sebastian and M{\"u}hlbauer, Christian and Sittl, Christopher and Rottengruber, Hermann and Rabl, Hans-Peter and Wagner, Marcus and Verhey, Jesko L.}, title = {Tickerger{\"a}uschanalyse an einem Otto-DI-Motor mittels empirischer Bewertungsformel}, series = {Motor- und Aggregate-Akustik: 11. Magdeburger Symposium, Tagungsband}, booktitle = {Motor- und Aggregate-Akustik: 11. Magdeburger Symposium, Tagungsband}, editor = {Rottengruber, Hermann and Luft, Tommy and Schneider, Sebastian}, publisher = {Otto-von-Guericke-Universit{\"a}t}, address = {Magdeburg}, isbn = {978-3-948749-02-6}, doi = {10.25673/36611}, pages = {65 -- 86}, abstract = {Beim Kauf eines Pkw wird der akustische Qualit{\"a}tseindruck eines Fahrzeugantriebstrangs stetig relevanter. Die wahrgenommene Ger{\"a}uschqualit{\"a}t des Motoraggregates nimmt hierbei eine Schl{\"u}sselrolle ein. Aufgrund der Auspr{\"a}gung einzelner St{\"o}rger{\"a}usche wird jene Ger{\"a}uschqualit{\"a}t negativ beeinflusst. Diese als unangenehm empfundenen Ger{\"a}uschkomponenten gilt es im Rahmen der Fahrzeugentwicklung weiter zu reduzieren, wobei die Identifikation und Bewertung st{\"o}render Ger{\"a}uschanteile am Motorgesamtger{\"a}usch Voraussetzungen f{\"u}r eine effektive Akustikoptimierung sind. Vor allem das impulshafte Tickerger{\"a}usch wird bei Otto-DI-Motoren als besonders l{\"a}stig eingestuft, weswegen dieser Beitrag darauf abzielt, die tickernden Ger{\"a}uschanteile aus dem Gesamtger{\"a}usch zu analysieren und zu bewerten. Hierzu wurde eine empirische Formel entwickelt, welche die tickernden Ger{\"a}uschanteile in ihrer Intensit{\"a}t in Grenzen einstufen kann. Diese ist rein empfindungsbasiert und besteht aus der Impulshaftigkeit, der Lautheit sowie der Sch{\"a}rfe des Motorgesamtger{\"a}usches. Wie auch bei anderen psychoakustischen Bewertungsskalen wurde die Benotung von 1 (sehr tickernd) bis 10 (nicht tickernd) vorgenommen. Anhand von H{\"o}rversuchen mithilfe einer Expertenjury konnte die Tickerger{\"a}uschbewertungsformel anschließend verifiziert werden. Hiernach kann pr{\"a}zise ausgesagt werden, in welchen Motorkennfeldbereichen das Tickerger{\"a}usch die Angenehmheit des Motorgesamtger{\"a}usches untergr{\"a}bt.}, language = {de} } @inproceedings{BruecklWildfeuerSchaechinger, author = {Br{\"u}ckl, Oliver and Wildfeuer, M. and Sch{\"a}chinger, J.}, title = {Systemdienstleistungen durch Biogasanlagen}, series = {Biogas in der Landwirtschaft - Stand und Perspektiven: 7. FNR/KTBL-Onlinetagung 29.-30.09.2021, Darmstadt}, booktitle = {Biogas in der Landwirtschaft - Stand und Perspektiven: 7. FNR/KTBL-Onlinetagung 29.-30.09.2021, Darmstadt}, address = {Darmstadt}, isbn = {978-3-945088-83-8}, pages = {92 -- 101}, subject = {Biogasanlage}, language = {de} } @inproceedings{JupkeReindlMeieretal., author = {Jupke, Michael and Reindl, Andrea and Meier, Hans and Niemetz, Michael}, title = {Bidirectional DC-DC Converter with Digital Droop Parameterization}, series = {26th 2021 International Conference on Applied Electronics (AE): 7-8 Sept. 2021 Pilsen, Czech Republic}, booktitle = {26th 2021 International Conference on Applied Electronics (AE): 7-8 Sept. 2021 Pilsen, Czech Republic}, editor = {Pinker, Jiř{\´i}}, publisher = {Institute of Electrical and Electronics Engineers}, isbn = {978-80-261-0972-3}, doi = {10.23919/AE51540.2021.9542920}, pages = {1 -- 6}, abstract = {The key for decentralized battery systems is a robust and communication-less control strategy for autonomous power sharing of parallel-connected DC-DC converters. Battery systems improve the reliability and quality of power supply in renewable energy systems and enable power supply for off-grid, mobile applications, including islanded grids, home storage, and electric vehicles. In many cases, components with different electrical properties require different voltage levels. An adaptation is consequently essential and is normally implemented in DC grids for the batteries via bidirectional DC-DC converters. The power flow in both directions can thus be ensured. To achieve a power distribution in parallel connected DC-DC converters, a droop control in the form of a virtual internal resistor can be used. This paper presents a novel approach of a DC-DC converter with a digitally parameterizable droop resistor, whose voltage regulation is based on an analog operational amplifier circuit to ensure low delays and robustness. The droop resistor is adjusted with a microcontroller, which offers the possibility to apply a higher-level control for load sharing via an interface. Mathematical correlations are used to clearly define the parameters of the control. Furthermore, the circuit was completely simulated and tested in the hardware setup. The shown results verify the functionality and indicate only minor deviations. Therefore, this circuit is important for future use in distributed battery systems.}, language = {en} } @inproceedings{ReindlSingerMeieretal., author = {Reindl, Andrea and Singer, Thomas and Meier, Hans and Niemetz, Michael and Park, Sangyoung}, title = {Framework to Test DC-DC Converters Developed for a Decentralized Battery Management System}, series = {2021 International Conference on Applied Electronics (AE): 7-8 Sept. 2021, Pilsen, Czech Republic}, booktitle = {2021 International Conference on Applied Electronics (AE): 7-8 Sept. 2021, Pilsen, Czech Republic}, publisher = {IEEE}, doi = {10.23919/AE51540.2021.9542882}, pages = {1 -- 6}, abstract = {DC- DC converters control the power flow and thus the power distribution between the components on different voltage levels. They are essential for (dis)charging batteries and influence the safety and stability of the entire battery management system (BMS). Therefore, testing the functionality and the reliability of DC-DC converters is crucial. This is especially true for decentralized battery management systems (DBMS), where multiple nodes communicate to collectively control the system. The used DC-DC converters are modified to parameterize them during operation via microcontroller interfaces. Integrating the communication into the control loop requires an analysis of the control behavior due to additional delays. Therefore, this paper proposes a framework to test DC-DC converters considering the control and communication perspectives. The response time, the control accuracy and stability of these DC-DC converters, e.g., under continuous and abrupt load changes, are measured in automated tests. The dedicated software framework simulates the DBMS and stimulates the hardware components (e.g. electronic loads, data acquisition) via respective interfaces (CAN, RS232). This allows the test of various DC-DC converters with flexibly adaptable load and power generation profiles. An initial application validates the test framework by verifying the aforementioned aspects and thus the applicability of a DC-DC converter within the DBMS.}, language = {en} } @inproceedings{ReindlMeierNiemetzetal., author = {Reindl, Andrea and Meier, Hans and Niemetz, Michael and Park, Sangyoung}, title = {Decentralized Battery Management System with Customized Hardware Components}, series = {IEEE 19th Student Conference on Research and Development (SCOReD), Sustainable Engineering and Technology towards Industry Revolution: 23-25 Nov. 2021, Kota Kinabalu, Malaysia}, booktitle = {IEEE 19th Student Conference on Research and Development (SCOReD), Sustainable Engineering and Technology towards Industry Revolution: 23-25 Nov. 2021, Kota Kinabalu, Malaysia}, publisher = {IEEE}, doi = {10.1109/SCOReD53546.2021.9652737}, pages = {350 -- 355}, abstract = {With an increasing number of sold electric vehicles (EVs), a large number of used batteries will be at disposal. How to deal with these resources is one of the major challenges in reducing the environmental impact of batteries throughout their entire life cycle. Heterogeneous cell parameters due to the different usage histories are a challenge for second-life use. The effort and cost of remanufacturing required to test and assemble a new battery pack is a further concern. Systems that combine battery packs/modules without full reassembly offer advantages such as cost and reusability. A decentralized battery management system (DBMS) provides a suitable architecture for such systems involving different types of batteries. In this paper, an architecture for a decentralized, battery state-dependent control is shown. The proposed DBMS supports various types of batteries, is scalable and flexibly adaptable for a wide range of applications. Despite the significant advantages, there are increased requirements to meet for the hardware implementation and the applied control strategies. Therefore, the necessary hardware components and their requirements are described and the hardware implementations are provided.}, language = {en} } @inproceedings{SchubertLeeOoi, author = {Schubert, Martin J. W. and Lee, Wai-Kong and Ooi, Boon Yaik}, title = {Quantization and Sampling Effects in Fast Digitally Controlled Switch-Mode DC/DC Buck Converters}, series = {2021 IEEE Industrial Electronics and Applications Conference (IEACon): 22.11.2021 - 23.11.2021, Penang, Malaysia}, booktitle = {2021 IEEE Industrial Electronics and Applications Conference (IEACon): 22.11.2021 - 23.11.2021, Penang, Malaysia}, publisher = {IEEE}, isbn = {978-1-7281-9253-6}, doi = {10.1109/IEACon51066.2021.9654272}, pages = {56 -- 61}, abstract = {Software-defined control of DC/DC switch mode power converters features unequaled flexibility compared to analog control. For fast switching converters as recently used for low power applications, digital control may cause steady-state oscillations known as limit cycles. This effect based on a quantized duty cycle is compared to other aberrations such as output ripple voltage, which is inherent to any pulse-width modulator. A distinction is made between DC and AC errors. The latter are divided into synchronous and asynchronous output voltage disturbances. Synchronous AC errors are composed of the switching frequency and its harmonics.}, language = {en} } @inproceedings{CroceDiamantidisSykora, author = {Croce, Valeria and Diamantidis, Dimitris and S{\´y}kora, Miroslav}, title = {Planning post earthquake surveys: assessments and reconstruction of small historical centres}, series = {1st IABSE Online Symposium 2020, Synergy of culture and civil engineering - history and challenges: Wrocław, Poland, 7-9 October 2020, Proceedings}, booktitle = {1st IABSE Online Symposium 2020, Synergy of culture and civil engineering - history and challenges: Wrocław, Poland, 7-9 October 2020, Proceedings}, editor = {Bien, Jan}, publisher = {Curran Associates Inc}, address = {Red Hook, NY}, isbn = {978-1-7138-2387-2}, pages = {332 -- 339}, abstract = {The contribution presents a methodological procedure for the management and planning of interventions after earthquake events in small historic centres. Reference is made to the case study of Castelluccio di Norcia, a village in the Apennine Mountains affected by the seismic sequence that hit Central Italy in 2016. The earthquake risk of the area and the damaging events of 2016 are critically reviewed. The implementation of cognitive analysis and the application of advanced survey techniques involving the use of nmanned Aerial Vehicles (UAVs) for the purposes of emergency management and monitoring of damaged areas are analysed. The outcomes, combined with the direct involvement of the local population, represent a complete and integrated approach allowing the definition of a) possible intervention strategies, b) related decision criteria and c) practical recommendations for the reconstruction and regeneration of Castelluccio, and, in general, of small historic centres damaged by catastrophic events.}, language = {en} } @techreport{GerhardsWeberKlafkaetal., author = {Gerhards, Christoph and Weber, Urban and Klafka, Peter and Golla, Stefan and Hagedorn, Gregor and Baumann, Franz and Brendel, Heiko and Breyer, Christian and Clausen, Jens and Creutzig, Felix and Daub, Claus-Heinrich and Helgenberger, Sebastian and Hentschel, Karl-Martin and von Hirschhausen, Christian and Jordan, Ulrike and Kemfert, Claudia and Krause, Harald and Linow, Sven and Oei, Pao-Yu and Pehnt, Martin and Pfennig, Andreas and Pr{\"a}ger, Fabian and Quaschning, Volker and Schneider, Jens and Spindler, Uli and Stelzer, Volker and Sterner, Michael and Wagener-Lohse, Georg and Weinsziehr, Theresa}, title = {Klimavertr{\"a}gliche Energieversorgung f{\"u}r Deutschland - 16 Orientierungspunkte}, series = {Diskussionsbeitr{\"a}ge der Scinetists for Future ; 7}, journal = {Diskussionsbeitr{\"a}ge der Scinetists for Future ; 7}, doi = {10.5281/zenodo.4409334}, abstract = {Als fairer Beitrag Deutschlands zur Einhaltung der globalen 1,5-Grad-Grenze werden 16 Orientierungspunkte f{\"u}r eine klimavertr{\"a}gliche Energieversorgung vorgestellt. Es wird davon ausgegangen, dass hierf{\"u}r die deutschen energiebedingten CO2-Emissio­nen in etwa 15 Jahren weitgehend auf Null sinken m{\"u}ssen. Energieeinsparung hilft, den notwendigen Ausbau von regenerativen Erzeugungskapazit{\"a}ten zu verringern. Der Verkehrssektor kann ebenso wie die Bereiche Prozess- und Geb{\"a}udew{\"a}rme hier­zu wesentlich beitragen. Die Kernenergie ist mit großen Risiken belastet und kann nicht hinreichend schnell aufgebaut werden. Biomasse in Form von Energie­pflan­zen zu nutzen, ist ineffizient und steht im Konflikt mit anderen Arten der Land­nut­zung. Importe klimaneutral erzeugter Energietr{\"a}ger in sehr großem Umfang er­for­dern extrem große Investitionen im Ausland. Sie sind eine ungesicherte Option auf die Zukunft. Entscheidend ist daher der ausreichend schnelle Ausbau von Photovoltaik (PV) und Wind­kraft in Deutschland. Sch{\"a}tzungsweise kann der Elektrizit{\"a}tsbedarf im Jahr 2030 z.B. durch den Ausbau auf ca. 350 GW PV und ca. 150 GW Windkraft nahe­zu voll­st{\"a}ndig regenerativ gedeckt werden. Damit ließe sich eine zum großen Teil elek­tri­fizierte Mobilit{\"a}t und W{\"a}rmeversorgung betreiben und ein Teil des ben{\"o}­tig­ten "gr{\"u}­nen" Wasserstoffs in Deutschland bereitstellen. Hierf{\"u}r ist ein j{\"a}hr­licher Zu­bau von durchschnittlich ca. 30 GW PV und ca. 9 GW Windkraft n{\"o}tig. Dies ist ca. sechs- (PV) bzw. dreimal (Wind) so hoch wie bisher vorgesehen und verlangt eine ge­sell­schaft­liche Kraftanstrengung. Ein weiter verz{\"o}gerter Ausbau m{\"u}sste mit noch deut­lich gr{\"o}ßeren gesellschaftlichen Anstrengungen f{\"u}r drastische Energieeinspa­run­gen oder Importe erneuerbarer Energie ausgeglichen werden. Insgesamt k{\"o}nnte dies noch deutlich schwieriger zu realisieren sein, als ein ambitionierter Ausbau. Da der Auf­bau der Kapazit{\"a}ten mehrere Jahre erfordert, ist es m{\"o}glich nachzusteuern, z. B. wenn erkennbar wird, dass sich ein ausreichend großer globaler Markt f{\"u}r Importe ent­wi­ckelt. Bis dahin ist es aus Verantwortung gegen­{\"u}ber der Zukunft und im Sinne des Pariser Vertrages empfehlenswert, die hier genannten Ausbauziele zu verfol­gen. Gr{\"u}ner, also aus erneuerbaren Energien hergestellter Wasserstoff und daraus abge­lei­tete Syntheseprodukte sind f{\"u}r die Dekarbonisierung von Industrieprozessen, den Flug- und Schiffsverkehr sowie f{\"u}r die Absicherung der Energieversorgung bei Dun­kel­flauten n{\"o}tig. Ohne die genannten Ausbauziele f{\"u}r Wind und Solar noch drastisch weiter zu erh{\"o}hen, stehen diese Produkte f{\"u}r Straßenverkehr und W{\"a}rmeversor­gung jedoch nicht in ausreichenden Mengen zur Verf{\"u}gung. Techniken zum Aus­gleich zwischen Elektrizit{\"a}tsangebot und -nachfrage sind verf{\"u}gbar und sollten recht­zeitig auf- bzw. ausgebaut werden. Hierzu geh{\"o}ren: Stromaustausch mit den Nach­barl{\"a}ndern, Flexibilisierung des Verbrauchs und Energiespeicherung. F{\"u}r deren Inte­gration sowie den Ausbau der Netze sollten z{\"u}gig verbesserte rechtliche Rah­men­bedingungen geschaffen werden. Die Kosten eines klimavertr{\"a}glichen Energiesystems sind mittel- bis langfristig nicht h{\"o}­her als im derzeitigen System. Gleichzeitig entstehen Arbeitspl{\"a}tze und Export­chan­cen durch Aufbau, Betrieb und Wartung einer regenerativen Energieversorgung in Deutschland und die energetische Geb{\"a}udesanierung. Die politischen Rahmenbe­din­gungen entscheiden, ob eine klimavertr{\"a}gliche Energieversorgung Deutschlands ge­lingt.}, language = {de} } @inproceedings{GoetzRauchBrueckl, author = {Goetz, Rebecca and Rauch, Johannes and Br{\"u}ckl, Oliver}, title = {Techno-economic analysis of reactive power sources}, series = {NEIS 2021, Conference on Sustainable Energy Supply and Energy Storage Systems: Hamburg, 13.-14. September 2021}, booktitle = {NEIS 2021, Conference on Sustainable Energy Supply and Energy Storage Systems: Hamburg, 13.-14. September 2021}, editor = {Schulz, Detlef}, publisher = {VDE-Verlag}, isbn = {978-3-8007-5651-3}, pages = {286 -- 291}, abstract = {This paper presents different options to provide reactive power in electricity grid systems. Since conventional power plants are being phased out and the reactive power demand tends to increase, alternative technologies are needed to cover it. reactive power sources are being defined and specified in this submission. A technical evaluation and an economic analysis of selected reactive power sources are carried out, based on interviews with manufacturers and operators. As well a multifactorial techno-economic comparison of the evaluated reactive power sources is presented. The technical analysis addresses reactive power control-ranges, stochastic parameters, lifespans, electrical losses and dynamics of re-active power sources. It states that power electronics allow faster setpoint changes than mechanical technologies can achieve, but at the same time this is associated with the highest electrical losses of the reactive power sources considered here. Considering the economic analysis, relative investment costs per reactive power of conventional compensation systems turn out to be the most cost-efficient. With regard to the multifactorial techno-economic comparison, it is im-portant not only to standardize on reactive power that can be provided, but also to include the additional system-relevant properties of technologies in the evaluation as well as the costs in operation.}, language = {en} } @techreport{SternerSchummRanketal., author = {Sterner, Michael and Schumm, Leon and Rank, Daniel and Hofrichter, Andreas}, title = {Intelligente Netzpuffer : Abschlussbericht (24.01.2021)}, language = {de} } @inproceedings{GrauvoglStauderHopfenspergeretal., author = {Grauvogl, Dominik and Stauder, Peter and Hopfensperger, Bernhard and Gerling, Dieter}, title = {Multiphysics Design of a Wound Field Synchronous Machine with Magnetic Asymmetry}, series = {Proceedings of the 2021 IEEE International Electric Machines \& Drives Conference (IEMDC): 17-20 May 2021, Hartford, CT, USA}, booktitle = {Proceedings of the 2021 IEEE International Electric Machines \& Drives Conference (IEMDC): 17-20 May 2021, Hartford, CT, USA}, doi = {10.1109/IEMDC47953.2021.9449564}, abstract = {In this paper a multiphysics development method is used for designing a novel wound field synchronous machine of the future generation of high voltage traction drives. This method covers the domains of electromagnetics, the mechanical strength, thermal behavior and the magnetic noise. It is shown that the proposed novel asymmetric design with a circular flux barrier in combination with an asymmetric pole offset is fulfilling the requirements according to performance and torque ripple. A fatigue strength rotor mechanic concept is included. A hybrid cooling concept consisting of a water jacket cooled stator and air cooled rotor ensures the needed continuous power. Unacceptable noise levels are excluded by investigating the equivalent radiated power (ERP) level due to radial forces in the air gap. Finally, the multi-physical workflow resulted in a fully developed component with a high degree of maturity.}, language = {en} } @inproceedings{GrauvoglKrabinskiStauderetal., author = {Grauvogl, Dominik and Krabinski, Jeffrey and Stauder, Peter and Hopfensperger, Bernhard and Gerling, Dieter}, title = {NVH Comparison of a Novel Wound Field Synchronous Machine with Magnetic Asymmetry with a PSM for a HV Electric Drive}, series = {2021 JSAE Annual Congress (Spring) Proceedings; online meeting (No.76-21)}, booktitle = {2021 JSAE Annual Congress (Spring) Proceedings; online meeting (No.76-21)}, publisher = {JSAE}, abstract = {This paper shows how magnetic noises can be reduced with a wound field synchronous machine (WFSM) with magnetic asymmetry compared to a permanent magnet synchronous machine (PSM), operating at base speed range and full load. In order to reproduce a real noise behavior, the two rotor types are operated in a complete electric drive unit (EDU) consisting of an electric motor, gearbox, inverter and overall housing. In the concept study, the noise characteristics of the two electric machines is evaluated and compared via mechanical finite element method (FEM) simulations using the equivalent radiated power (ERP) level and Campbell diagrams. Furthermore, it is shown that critical frequency orders can already be identified by the analysis of the magnetic force density from the electromagnetic design without computationally intensive ERP calculations. In this context, the ERP investigations have shown that the unique feature of the magnetically asymmetric WFSM is the reduction of the slot harmonics. At the current state of the art, the slot harmonics can only be reduced with a rotor skewing. The disadvantage of this is a reduction in performance and a more expensive production. It is also remarkable that the magnetic asymmetry reduces the slot harmonics more than the rotor skewing in the PSM. In addition, both machines are still considered with a short-pitched stator winding to optimize the overall noise level by reducing the 24th frequency order.}, subject = {Elektroantrieb}, language = {en} } @inproceedings{SteiningerGadererDawoud, author = {Steininger, Peter and Gaderer, Matthias and Dawoud, Belal}, title = {Transient performance of a solar selective thermal insulation system}, series = {16th Advanced Building Skins Conference \& Expo, 21 - 22/10/2021, Bern, Switzerland}, booktitle = {16th Advanced Building Skins Conference \& Expo, 21 - 22/10/2021, Bern, Switzerland}, publisher = {Advanced Buidling Skins GmbH}, abstract = {A prototype of a thermal insulation system to offer high selectivity of the solar gain regarding the solar incidence angle (SATIS) was applied to a typical solid brick masonry for existing buildings in Germany. Light conducting elements (LCEs) inclined at 19 ° were incorporated in SATIS, which equals the average solar noon angle in southern Germany during winter. The entire wall construction was experimentally investigated in a differential climatic chamber test bench at four different irradiation angles according to a dynamic test procedure. In addition, a conventional wall construction (CWC) has been measured. At SATIS' design angle of 19 °, the SATIS wall construction shows a solar gain (SG) of 394.5 Wh/m², while the SG of the CWC amounts to only 25.4 Wh/m². The validated transient model of the SATIS wall construction showed that, at the end of the irradiation period of the dynamic test procedure (8 h), the solar heat penetrates to a depth of 253 mm and 111 mm inside the 385 mm thick brick wall masonry at the irradiation angles of 19 ° and 50 °, respectively. During the same time, the stored solar energy at 50 ° amounts to only 24.4 \% of that stored at 19 °.}, language = {en} } @techreport{ThemaKaulSterneretal., author = {Thema, Martin and Kaul, Anja and Sterner, Michael and Heberl, Michael}, title = {Optimierung eines Rieselbett-Bioreaktors f{\"u}r die dynamische mikrobielle Biosynthese von Methan mit Archaeen-Mikroorganismen in Power-to-Gas-Anlagen}, doi = {10.2314/KXP:1815321555}, abstract = {Das {\"u}bergeordnete Ziel des Vorhabens war die Entwicklung neuer technologischer M{\"o}glichkeiten f{\"u}r den biologischen Methanisierungsprozess mit Archaeen1 in Power-to-Gas-Anwendungen. Im Gegensatz zur technisch ausgereiften chemisch-katalytischen Methanisierung sind hier noch Potenziale zur Optimierung verfahrenstechnischer und biologischer Prozesse f{\"u}r das Speicherkonzept Power-to-Gas [7] vorhanden. Dabei sollte zum einen ein Rieselbett-Bioreaktor optimiert, simuliert und f{\"u}r die Hochskalierung vorbereitet werden. Zum anderen sollte eine Kombination optimal geeigneter Mikroorganismen und Packungsmaterialien selektiert und deren Verhalten und Eignung im Reaktor analysiert werden. Das Verhalten des entwickelten Systems sollte zun{\"a}chst im Labor- und Technikumsmaßstab und anschließend im Feldtest an einer bestehenden Power-to-Gas-Anlage untersucht werden. Hauptziel w{\"a}hrend des Feldtests war die Produktion von einspeisef{\"a}higem Methan sowie dessen Einspeisung ins Gasnetz. Ein Hauptziel des Projektes war es, die Normung und Standardisierung notwendiger Systemparameter und Semantik zur Beschreibung und Einbindung biologischer Methanisierungseinheiten in Power-to-Gas-Anlagen voranzutreiben. Dies sollte zum einen die Vergleichbarkeit der wissenschaftlichen Erkenntnisse verbessern und zum anderen unterst{\"u}tzend bei der Kommerzialisierung der Technologie wirken. Aus dem Projekt heraus wurde so die neue Normungsreihe VDI 4635 Power-to-X beim Verein Deutscher Ingenieure angestoßen.}, language = {de} } @inproceedings{KlitsmanBruecklEller, author = {Klitsman, Maksym and Br{\"u}ckl, Oliver and Eller, Johannes}, title = {Analysis and simulation of the population driving behaviour and charging processes at different charging station types with electric vehicles}, series = {NEIS 2021, Conference on Sustainable Energy Supply and Energy Storage Systems: 13-14. September 2021, Hamburg}, booktitle = {NEIS 2021, Conference on Sustainable Energy Supply and Energy Storage Systems: 13-14. September 2021, Hamburg}, editor = {Schulz, Detlef}, publisher = {VDE-Verlag}, isbn = {978-3-8007-5651-3}, pages = {254 -- 260}, abstract = {Electric vehicles are one of the important components of the energy transition, which is necessary for the CO2 emission reduction. In order to estimate the influence of electromobility on electric grids at present day and in the future, the generation of realistic charge profiles is necessary. The main objective of this study is the development of an algorithm, which generates realistic charge time series of electric vehicles. The very huge and detailed input surveys enable to define different population groups, representing specific driving behaviour. These groups are then composed and scaled up, according to the statistical population structure of a chosen town or city in Germany, and show typical driving behaviour of all inhabitants. The charge profiles are calculated for several charge station types, based on daily electric vehicle user mobility, day type and household type. In addition, charge process occurrence is evaluated through a model, involving charge infrastructure presence, attractiveness of corresponding charge station type and charge process necessity.}, language = {en} } @misc{PershinaSavelievGlavanetal., author = {Pershina, K. V. and Saveliev, Dmitry V. and Glavan, Gašper and Chashin, Dmitri V. and Belyaeva, Inna A. and Fetisov, Leonid Y. and Shamonin (Chamonine), Mikhail}, title = {The voltage response of a structure comprising a magnetoactive-elastomer cylinder and a piezoelectric material to magnetic field step excitations}, series = {The 4th International Baltic Conference on Magnetism (IBCM 2021) : Svetlogorsk, Russia August 29 - September 2, 2021 : Book of Abstracts}, journal = {The 4th International Baltic Conference on Magnetism (IBCM 2021) : Svetlogorsk, Russia August 29 - September 2, 2021 : Book of Abstracts}, publisher = {Immanuel Kant Baltic Federal University, Kaliningrad, Russia}, pages = {182}, language = {en} } @misc{SternerHeberl, author = {Sterner, Michael and Heberl, Michael}, title = {The ORBIT-Project: Biological methanation in a trickle-bed reactor - key results and next steps}, series = {5th Nuremberg Workshop on Methanation and 2nd Generation, N{\"u}rnberg Friedrich-Alexander-Universit{\"a}t, 28.05.2021}, journal = {5th Nuremberg Workshop on Methanation and 2nd Generation, N{\"u}rnberg Friedrich-Alexander-Universit{\"a}t, 28.05.2021}, organization = {Friedrich-Alexander-Universit{\"a}t Erlangen-N{\"u}rnberg / Lehrstuhl f{\"u}r Energieverfahrenstechnik}, language = {en} } @article{RillBauerKirchbeck, author = {Rill, Georg and Bauer, Florian and Kirchbeck, Mathias}, title = {VTT - a virtual test truck for modern simulation tasks}, series = {Vehicle system dynamics}, volume = {59}, journal = {Vehicle system dynamics}, number = {4}, publisher = {Taylor\&Francis}, doi = {10.1080/00423114.2019.1705356}, pages = {635 -- 656}, abstract = {The development of new technologies like advanced driver assistance systems or automated driving requires a flexible simulation environment of sufficient complexity. In general this flexibility is not provided by commercial software packages. This paper presents a three-dimensional and nonlinear hand-made model for heavy commercial vehicles including tractor and trailer as well as tractor and semitrailer combinations that can be used in different simulation environments, as well as in real-time applications. As typical for trucks, the torsional flexibility of the frame and a suspended driver's cabin are taken into account. The design kinematics makes it possible to handle different and quite complex axle suspensions very efficiently. Appropriate force elements are used to model various couplings between tractor and trailer or tractor and semitrailer, respectively. The virtual test truck environment (VTT) coded in ANSI C is extremely portable and can easily be embedded in commercial simulation packages like MATLAB/Simulink. It includes the TMeasy tyre model and offers flexible interfaces to third-party software tools.}, language = {en} } @article{RillBauerTopcagic, author = {Rill, Georg and Bauer, Florian and Topcagic, Edin}, title = {Performance of leaf spring suspended axles in model approaches of different complexities}, series = {Vehicle System Dynamics}, volume = {60}, journal = {Vehicle System Dynamics}, number = {8}, publisher = {Taylor\&Francis}, doi = {10.1080/00423114.2021.1928249}, pages = {2871 -- 2889}, abstract = {Axles with leaf spring suspension systems are still a popular choice in many commercial vehicles. However, leaf springs are not in perfect conformity to standard multibody vehicle models because they combine guidance and suspension in one single element. Combining standard multibody vehicle models with sophisticated finite element leaf spring models results in rather complex and computing time-consuming solutions. Purely kinematic models, defined by lookup tables or the design kinematics approach, cover only some but not all features of the leaf spring suspension. As shown here, the five-link model, which incorporates a quasi-static solution of the leaf spring compliance, provides a very practical model. It is comparatively lean and provides results of sufficient accuracy in the whole application range.}, language = {en} } @misc{Sterner, author = {Sterner, Michael}, title = {Strom - W{\"a}rme - Verkehr - Industrie: das Zusammenspiel der Sektoren {\"u}ber Power-to-X}, series = {Deutscher Ingenieurtag 2021, D{\"u}sseldorf 20. Mai 2021}, journal = {Deutscher Ingenieurtag 2021, D{\"u}sseldorf 20. Mai 2021}, publisher = {VDI-Verlag}, language = {de} } @article{FrazzicaPalombaDawoud, author = {Frazzica, Andrea and Palomba, Valeria and Dawoud, Belal}, title = {Thermodynamic Performance of Adsorption Working Pairs for Low-Temperature Waste Heat Upgrading in Industrial Applications}, series = {Applied Sciences}, volume = {11}, journal = {Applied Sciences}, number = {8}, publisher = {MDPI}, doi = {10.3390/app11083389}, abstract = {The present work aims at the thermodynamic analysis of different working pairs in adsorption heat transformers (AdHT) for low-temperature waste heat upgrade in industrial processes. Two different AdHT configurations have been simulated, namely with and without heat recovery between the adsorbent beds. Ten working pairs, employing different adsorbent materials and four different refrigerants, have been compared at varying working boundary conditions. The effects of heat recovery and the presence of a temperature gradient for heat transfer between sinks/sources and the AdHT components have been analyzed. The achieved results demonstrate the possibility of increasing the overall performance when internal heat recovery is implemented. They also highlight the relevant role played by the existing temperature gradient between heat transfer fluids and components, that strongly affect the real operating cycle of the AdHT and thus its expected performance. Both extremely low, i.e., 40-50 degrees C, and low (i.e., 80 degrees C) waste heat source temperatures were investigated at variable ambient temperatures, evaluating the achievable COP and specific energy. The main results demonstrate that optimal performance can be achieved when 40-50 K of temperature difference between waste heat source and ambient temperature are guaranteed. Furthermore, composite sorbents demonstrated to be the most promising adsorbent materials for this application, given their high sorption capacity compared to pure adsorbents, which is reflected in much higher achievable specific energy.}, language = {en} } @article{ThemaWeidlichKauletal., author = {Thema, Martin and Weidlich, Tobias and Kaul, Anja and B{\"o}llmann, Andrea and Huber, Harald and Bellack, Annett and Karl, J{\"u}rgen and Sterner, Michael}, title = {Optimized biological CO2-methanation with a pure culture of thermophilic methanogenic archaea in a trickle-bed reactor}, series = {Bioresource Technology}, journal = {Bioresource Technology}, number = {333}, publisher = {Elsevier}, doi = {10.1016/j.biortech.2021.125135}, abstract = {In this study, a fully automated process converting hydrogen and carbon dioxide to methane in a high temperature trickle-bed reactor was developed from lab scale to field test level. The reactor design and system performance was optimized to yield high methane content in the product gas for direct feed-in to the gas grid. The reaction was catalyzed by a pure culture of Methanothermobacter thermoautotrophicus IM5, which formed a biofilm on ceramic packing elements. During 600 h in continuous and semi-continuous operation in countercurrent flow, the 0.05 m3 reactor produced up to 95.3 \% of methane at a methane production rate of 0.35 mCH43mR-3h-1. Adding nitrogen as carrier gas during startup, foam control and dosing of ammonium and sodium sulfide as nitrogen and sulfur source were important factors for process automation.}, language = {en} } @article{SchorrZentnerZimmermannetal., author = {Schorr, Philipp and Zentner, Lena and Zimmermann, Klaus and B{\"o}hm, Valter}, title = {Jumping locomotion system based on a multistable tensegrity structure}, series = {Mechanical systems and signal processing}, journal = {Mechanical systems and signal processing}, number = {152}, publisher = {Elsevier}, doi = {10.1016/j.ymssp.2020.107384}, abstract = {All known locomotion principles are limited respective to environmental conditions. Often, the occurrence of obstacles or gaps means the break-off for the operating motion systems. For such circumstances, a controllable jumping locomotion is required to cross these barriers. However, this locomotion demands sophisticated requirements to the actuation. The abrupt actuation is commonly realized by high dynamic actuators or complex mechanisms. In this work, a simple solution utilizing the multistability of a compliant tensegrity structure is described. Therefore, a two-dimensional tensegrity structure featuring four stable equilibria is considered. Based on bifurcation analyses a feasible actuation to control the current equilibrium configuration is derived. Changing between selected equilibrium states enables a great difference in potential energy, which yields a jumping motion of the structure. Based on numerical simulations a suitable actuation strategy is chosen to overcome obstacle and steps by jumping forward or backward, respectively. The theoretical approach is examined experimentally with a prototype of the multistable tensegrity structure. (c) 2020 Elsevier Ltd. All rights reserved. All known locomotion principles are limited respective to environmental conditions. Often, the occurrence of obstacles or gaps means the break-off for the operating motion systems. For such circumstances, a controllable jumping locomotion is required to cross these barriers. However, this locomotion demands sophisticated requirements to the actuation. The abrupt actuation is commonly realized by high dynamic actuators or complex mechanisms. In this work, a simple solution utilizing the multistability of a compliant tensegrity structure is described. Therefore, a two-dimensional tensegrity structure featuring four stable equilibria is considered. Based on bifurcation analyses a feasible actuation to control the current equilibrium configuration is derived. Changing between selected equilibrium states enables a great difference in potential energy, which yields a jumping motion of the structure. Based on numerical simulations a suitable actuation strategy is chosen to overcome obstacle and steps by jumping forward or backward, respectively. The theoretical approach is examined experimentally with a prototype of the multistable tensegrity structure.}, language = {en} } @article{PalombaNowakDawoudetal., author = {Palomba, Valeria and Nowak, Sebastian and Dawoud, Belal and Frazzica, Andrea}, title = {Dynamic modelling of Adsorption systems: a comprehensive calibrated dataset for heat pump and storage applications}, series = {Journal of energy storage}, volume = {33}, journal = {Journal of energy storage}, publisher = {Elsevier}, doi = {10.1016/j.est.2020.102148}, abstract = {The growing efforts for the development of clean and efficient energy systems require the use of a multi-disciplinary approach and the integration of multiple generation appliances. Among the fields that can be considered enabling technologies, adsorption systems for air conditioning and thermal energy storages, are constantly increasing their maturity. However, for a proper design and integration of such systems, there is the need for a simulation framework that is reliable and computationally convenient. In the present paper, the implementation of a dynamic model for adsorption systems is presented, which includes different components (adsorber, phase changer, sorption materials) and is structured as a library. Modelica language and the commercial software Dymola (R) are used for the analysis. Data for different heat exchangers and working pairs are calibrated using experimental results and the calibrated model is subsequently used for the design of an adsorber based on a plate heat exchanger for thermal energy storage applications. The results proved that the model is fast and can reproduce experimental results with good accuracy, thus being a useful tool for the design and optimization of the different components of sorption systems.}, language = {en} } @article{SovacoolCabezaPiselloetal., author = {Sovacool, Benjamin K. and Cabeza, Luisa F. and Pisello, Anna Laura and Colladon, Andrea Fronzetti and Larijani, Hatef Madani and Dawoud, Belal and Martiskainen, Mari}, title = {Decarbonizing household heating: Reviewing demographics, geography and low-carbon practices and preferences in five European countries}, series = {Renewable \& Sustainable Energy Reviews}, journal = {Renewable \& Sustainable Energy Reviews}, number = {139}, publisher = {Elsevier}, doi = {10.1016/j.rser.2020.110703}, pages = {1 -- 28}, abstract = {What commonalities are there in sustainable or unsustainable heating practices in five high-income, high-emitting western European countries? What preferences do a nationally representative sample of the public in these countries hold towards low-carbon options? It is imperative that climate policy researchers and practitioners grapple with the difficulty of decarbonizing heat, which remains the largest single end-use service worldwide and which accounts about half of total final energy consumption. Based on a comparative assessment of five representative national surveys in Germany (N = 2009), Italy (N = 2039), Spain (N = 2038), Sweden (N = 2023), and the United Kingdom (N = 2000), this study explores the demographics and geography of household heat decarbonisation in Europe. By analyzing our country level data as well as our combined sample of 10,109 respondents, it investigates how people conceive of the purposes of low-carbon heat, their preferences for particular forms of heat supply, and their (at times odd) practices of heat consumption and temperature settings. Grounded in its original data, the study organizes its findings inductively across the five themes of literacy (heating knowledge, awareness and control), sustainability (heating practices, dynamics and conflicts), temperature (heating satisfaction and preferences), desirability of change (low-carbon heating priorities, business models and trust), and culture (country and national variation). The study also explores intersections between these dimensions, using multivariate analysis, as well as how preferences differ according to varying types of actors as well as geography and space.}, language = {en} } @article{MonkmanSindersbergerPremetal., author = {Monkman, Gareth J. and Sindersberger, Dirk and Prem, Nina and Diermeier, Andreas and Szecsey, Tamara}, title = {Dielectric behaviour of magnetic hybrid materials}, series = {Physical Sciences Reviews}, volume = {7}, journal = {Physical Sciences Reviews}, number = {10}, publisher = {de Gruyter}, doi = {10.1515/psr-2019-0121}, pages = {1169 -- 1185}, abstract = {The objectives of this work include the analysis of electrical and magnetic properties of magneto-elastic hybrid materials with the intention of developing new techniques for sensor and actuator applications. This includes the investigation of dielectric properties at both low and high frequencies. The behaviour of capacitors whose dielectrics comprise magnetic hybrid materials is well known. Such interfacial magnetocapacitance can be varied according to magnetic content, magnetic flux density and the relative permittivity of the polymer matrix together with other dielectric content. The basic function of trapping electrical charges in polymers (electrets) is also established technology. However, the combination of magnetoactive polymers and electrets has led to the first electromagnetic device capable of adhering to almost any material, whether magnetically susceptible or not. During the course of this research, in addition to dielectrics, electrically conductive polymers based on (PDMS) matrices were developed in order to vary the electrical properties of the material in a targeted manner. In order to ensure repeatable results, this demanded new fabrication techniques hitherto unavailable. The 3D printing of silicones is far from being a mature technology and much pioneering work was necessary before extending the usual 3 d.o.f. to include orientation about and diffusion of particles in these three axes, thus leading to the concept of 6D printing. In 6D printing, the application of a magnetic field can be used during the curing process to control the particulate distribution and thus the spatial filler particle density as desired. Most of the devices (sensors and actuators) produced by such methods contain levels of carbonyl iron powder (CIP) embedded magnetic filler of up to 70 wt\%. Contrary to this, a hitherto neglected research area, namely magnetoactive polymers (MAPs) having significantly lower magnetic particle concentrations (1 to 3 wt\% CIP) were also investigated. With filler concentrations lower than 3 wt\%, structures are formed which are completely absent at higher filler levels. CIP concentrations in the range of 1wt\% demonstrate the formation of toroidal structures. Further development of coherent rings with a compact order results as filler concentrations increase towards 2 wt\%. Above 3 wt\% the structure eventually disintegrates to the usual random order found in traditional MAP with higher CIP content. Structured samples containing 1\%-3 wt\% CIP were investigated with the aid of X-ray tomography where solitary ring structures can be observed and eventually the formation of capillary doubles. Over wavelengths ranging from 1 to 25 µm, spectroscopic analysis of thin film MAP samples containing 2 wt\% CIP revealed measurable magnetic-field-dependent changes in IR absorption at a wavenumber 2350 (λ = 4.255 µm). This was found to be due to the diamagnetic susceptibility of atmospheric carbon dioxide (CO2). Consequently, the first potential application for sparse matrix MAPs was found.}, language = {en} } @article{SchwanzerSchillingerMieslingeretal., author = {Schwanzer, Peter and Schillinger, Maximilian and Mieslinger, Johann and Walter, Stefanie and Hagen, Gunter and Maerkl, Susanne and Haft, Gerhard and Dietrich, Markus and Moos, Ralf and Gaderer, Matthias and Rabl, Hans-Peter}, title = {A Synthetic Ash-Loading Method for Gasoline Particulate Filters with Active Oil Injection}, series = {SAR International Journal of Engines}, volume = {14}, journal = {SAR International Journal of Engines}, number = {4}, publisher = {SAE International}, issn = {1946-3936}, doi = {10.4271/03-14-04-0029}, pages = {493 -- 506}, abstract = {To reduce particulate emissions, the use of particulate filters in diesel engines is meanwhile state of the art, while the integration of such systems in gasoline engines is now also necessary in order to comply with today's regulations. Over its lifetime, a gasoline particulate filter (GPF) collects ash components of fuel, lubrication oil, and materials originating from the catalytic coating and from engine abrasion. In the development and application process, synthetic ashing from GPFs is challenging. The ash of the lubrication oil can be increased in various ways, like oil-doped fuel, a separate oil burner, or changes in the piston-cylinder system of the engine. However, these methods show major disadvantages. For this reason, an improved approach is presented in this study, which allows a quick response to changes in combustion (e.g., engine knocking) and producing ash, which is more realistic due to its primary particle size and the density of ash plugs, in a shorter time. Therefore, an approach to accelerate ash loading by active oil injection using a multi-point injection (MPI) system is introduced. With the help of this methodology, an ashing capacity of 1.21 g/h is implemented, which is a high rate compared to other investigations. The primary particle size (evaluated by means of a transmission electron microscope), is in the same size range as those detected at the full-load curve during regular operation. A computer tomographic (CT) analysis of the incinerated particulate filter also shows that a very high density of ash plugs can be realized, which has also been found in the literature for real applications. In addition, with the help of a mass spectrometer (MS) and an intermediate weighing of the particulate filter, the current ash loading of the GPF could be determined with an accuracy of 1\%.}, language = {en} } @article{SchmidtStraubSindersbergeretal., author = {Schmidt, Henrik and Straub, Benedikt B. and Sindersberger, Dirk and Br{\"o}ckel, Ulrich and Monkman, Gareth J. and Auernhammer, G{\"u}nter}, title = {Collision and separation of nickel particles embedded in a Poly dimethylsiloxan matrix under a rotating magnetic field: A strong magneto active function}, series = {Colloid and Polymer Science}, volume = {299}, journal = {Colloid and Polymer Science}, publisher = {Springer}, doi = {10.1007/s00396-020-04784-4}, pages = {955 -- 967}, abstract = {In order to function as soft actuators, depending on their field of use, magnetorheological elastomers (MREs) must fulfill certain criteria. To name just a few, these can include rapid response to external magnetic fields, mechanical durability, mechanical strength, and/or large deformation. Of particular interest are MREs which produce macroscopic deformation for small external magnetic field variations. This work demonstrates how this can be achieved by just a small change in magnetic field orientation. To achieve this, (super)paramagnetic nickel particles of size ≈ 160 μm were embedded in a non-magnetic polydimethylsiloxan (PDMS) (661-1301 Pa) and their displacement in a stepwise rotated magnetic field (170 mT) recorded using a video microscope. Changes in particle aggregation resulting from very small variations in magnetic field orientation led to the observation of a new strongly magneto-active effect. This configuration is characterized by an interparticle distance in relation to the angle difference between magnetic field and particle axis. This causes a strong matrix deformation which in turn demonstrates hysteresis on relaxation. It is shown that the occurrence strongly depends on the particle size, particle distance, and stiffness of the matrix. Choosing the correct parameter combination, the state can be suppressed and the particle-matrix system demonstrates no displacement or hysteresis. In addition, evidences of non-negligible higher order magnetization effects are experimentally ascertained which is qualitatively in agreement with similar, already theoretically described, particle systems. Even at larger particle geometries, the new strongly magneto-active configuration is preserved and could create macroscopic deformation changes.}, language = {en} } @inproceedings{RiegerOetjenvandeParetal., author = {Rieger, Anna and Oetjen, Arne and van de Par, Steven and Rabl, Hans-Peter}, title = {Geh{\"o}rbezogene Modellierung der Dissonanz}, series = {Tagungsband DAGA 2021: 47. Jahrestagung f{\"u}r Akustik, 15.-18. August 2021, Wien und Online}, volume = {47}, booktitle = {Tagungsband DAGA 2021: 47. Jahrestagung f{\"u}r Akustik, 15.-18. August 2021, Wien und Online}, publisher = {Deutsche Gesellschaft f{\"u}r Akustik e.V.}, pages = {1034 -- 1037}, language = {de} } @incollection{BauerGawlikSterneretal., author = {Bauer, Franz and Gawlik, Julia and Sterner, Michael and Hamacher, Thomas}, title = {{\"U}bergreifende Energiesystemmodellierung}, series = {Optionen f{\"u}r ein nachhaltiges Energiesystem mit Power-to-X-Technologien: Transformation - Anwendungen - Potentiale. 3. Roadmap des Kopernikus-Projektes P2X, Phase II}, booktitle = {Optionen f{\"u}r ein nachhaltiges Energiesystem mit Power-to-X-Technologien: Transformation - Anwendungen - Potentiale. 3. Roadmap des Kopernikus-Projektes P2X, Phase II}, editor = {Ausfelder, Florian and Dura, Hanna}, publisher = {DECHEMA Gesellschaft f{\"u}r Chemische Technik und Biotechnologie e.V.}, address = {Frankfurt a.M.}, isbn = {978-3-89746-236-6}, pages = {19 -- 33}, language = {de} } @article{LindnerPipaKarpenetal., author = {Lindner, Matthias and Pipa, Andrei V. and Karpen, Norbert and Hink, Ruediger and Berndt, Dominik and Foest, R{\"u}diger and Bonaccurso, Elmar and Weichwald, Robert and Friedberger, Alois and Caspari, Ralf and Brandenburg, Ronny and Schreiner, Rupert}, title = {Icing Mitigation by MEMS-Fabricated Surface Dielectric Barrier Discharge}, series = {Applied Sciences}, volume = {11}, journal = {Applied Sciences}, number = {23}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/app112311106}, pages = {1 -- 17}, abstract = {Avoiding ice accumulation on aerodynamic components is of enormous importance to flight safety. Novel approaches utilizing surface dielectric barrier discharges (SDBDs) are expected to be more efficient and effective than conventional solutions for preventing ice accretion on aerodynamic components. In this work, the realization of SDBDs based on thin-film substrates by means of micro-electro-mechanical-systems (MEMS) technology is presented. The anti-icing performance of the MEMS SDBDs is presented and compared to SDBDs manufactured by printed circuit board (PCB) technology. It was observed that the 35 mu m thick electrodes of the PCB SDBDs favor surface icing with an initial accumulation of supercooled water droplets at the electrode impact edges. This effect was not observed for 0.3 mu m thick MEMS-fabricated electrodes indicating a clear advantage for MEMS-technology SDBDs for anti-icing applications. Titanium was identified as the most suitable material for MEMS electrodes. In addition, an optimization of the MEMS-SDBDs with respect to the dielectric materials as well as SDBD design is discussed.}, language = {en} } @misc{SchwanzerDietrichGadereretal., author = {Schwanzer, Peter and Dietrich, Markus and Gaderer, Matthias and Rabl, Hans-Peter}, title = {Detektion unterschiedlicher Medien in Gasoline Particulate Filter (GPF) mit Hilfe eines Radio-Frequenz (RF-) Sensors}, series = {Bayerische Wissenschaftsforum - BayWISS 2020}, journal = {Bayerische Wissenschaftsforum - BayWISS 2020}, language = {de} } @book{AltmannGebhardEmbergeretal., author = {Altmann, Robert and Gebhard, J{\"u}rgen and Emberger, Peter and Thuneke, Klaus and Rabl, Hans-Peter and Remmele, Edgar}, title = {Z{\"u}nd- und Brennverhalten von Pflanzen{\"o}lkraftstoff und {\"U}bertragung auf einen Motor der Abgasstufe V}, volume = {69}, publisher = {Technologie- und F{\"o}rderzentrum im Kompetenzzentrum f{\"u}r Nachwachsende Rohstoffe}, address = {Straubing}, issn = {1614-1008}, pages = {188}, abstract = {Durch den Ersatz von Dieselkraftstoff durch Raps{\"o}lkraftstoff (R100) k{\"o}nnen Treibhausgasemissionen reduziert werden. F{\"u}r einen st{\"o}rungsfreien Betrieb eines Motors mit Raps{\"o}lkraftstoff sind jedoch Modifikationen an Motorkomponenten und Motorsteuerger{\"a}t notwendig, um eine effiziente Verbrennung im Motor zu erreichen. Ziel des Vorhabens ist die Erarbeitung von Grundlagen zur Auslegung der Motorsteuerung pflanzen{\"o}ltauglicher Offroad-Motoren mit moderner Abgasnachbehandlung mit anschließender entsprechender Abstimmung der Motorapplikation am Pr{\"u}fstand. Grundlegende Untersuchungen der physikalischen Prozessabl{\"a}ufe von R100 bei der Einspritzung werden an einem hydraulischen Druckanstiegsanalysator (HDA) und einer Hochdruck-Hochtemperatur-Kammer (HDHT-Kammer) durchgef{\"u}hrt. Unterschiede im Z{\"u}nd- und Brennverhalten werden in einer Konstantvolumenbrennkammer untersucht. Abschließend werden die Erkenntnisse am Motorenpr{\"u}fstand auf einen DEUTZ-Motor {\"u}bertragen, dessen Einspritzsystem auch bei den grundlegenden Untersuchungen verwendet wurde. Die Ergebnisse zeigen, dass das Einspritzverhalten von R100 eine h{\"o}here Sensitivit{\"a}t gegen{\"u}ber Kraftstofftemperaturvariationen aufweist als Dieselkraftstoff. Bei niedrigen raftstofftemperaturen sind mit R100 ein l{\"a}ngerer {\"O}ffnungsverzug und eine geringere Einspritzmenge festzustellen. Um diesen Einfluss bei der Einspritzstrategie zu kompensieren, ist die Kenntnis der Kraftstofftemperatur im Injektor notwendig. Eine weitere Herausforderung stellt die Gemischaufbereitung dar, hier f{\"u}hren unter anderem die h{\"o}here Viskosit{\"a}t und h{\"o}here Siedetemperaturen von R100 zu einem schm{\"a}leren Spritzwinkel und verz{\"o}gerter Verdampfung im Vergleich zum Dieselkraftstoff. Eine Erh{\"o}hung des Einspritzdrucks und h{\"o}here Temperaturen und Dr{\"u}cke in der Brennkammer verbessern die Gemischaufbereitung. Bei Bedingungen von mittlerer und hoher Last ist der Z{\"u}ndverzug von R100 k{\"u}rzer und das Verbrennungsverhalten {\"a}hnlich zum Dieselkraftstoff. Eine geringere W{\"a}rmefreisetzung von R100 wird durch den geringeren Heizwert verursacht. Unter Bedingungen von niedriger Last und Motorstart ist ein l{\"a}ngerer Z{\"u}ndverzug von R100 im Vergleich zum Dieselkraftstoff festzustellen. Eine Steigerung des Einspritzdrucks und h{\"o}here Brennkammerdr{\"u}cke und -temperaturen f{\"u}hren bei beiden Kraftstoffen zu k{\"u}rzeren Z{\"u}ndverz{\"u}gen, der Einfluss dieser Parameter ist jedoch f{\"u}r R100 st{\"a}rker als f{\"u}r Dieselkraftstoff. Voreinspritzungen f{\"u}hren bei beiden Kraftstoffen zu einer Verk{\"u}rzung des Z{\"u}ndverzugs der Haupteinspritzung und zu einer geringeren W{\"a}rmefreisetzungsrate. Am Motorpr{\"u}fstand ist bei gleicher Motorapplikation mit R100 eine geringere Leistung als mit Dieselkraftstoff festzustellen. Nach Angleichung der Motorleistung durch Anhebung der Einspritzmenge von R100 sind im Rohabgas Stickstoffoxid (NOX)- und Kohlenstoffmonoxidemissionen auf gleichem Niveau zu Dieselkraftstoff zu beobachten sowie geringere Partikelemissionen. Unter Verwendung eines DoE Vorgehens kann der Partikel-NOX - trade-off von R100 optimiert und Einstellparameter gefunden werden, in denen sowohl niedrigere NOX als auch niedrigere Partikelemissionen im Vergleich zum Dieselkraftstoff resultieren. Das installierte Abgasnachbehandlungssystem, bestehend aus einem Dieseloxidationskatalysator (DOC), Dieselpartikelfilter (DPF) und selektivem katalytischem Reduktionssystem (SCR), arbeitet f{\"u}r beide Kraftstoffe {\"a}hnlich und es scheint keine Anpassung der Dosierungsstrategie der w{\"a}ssrigen Harnstoffl{\"o}sung notwendig zu sein. Eine Regeneration des Partikelfilters mit R100 war nach Optimierung der Einstellparameter der Drosselklappe m{\"o}glich. Motorkaltstart und Leerlauf sind herausfordernde Betriebsphasen, die f{\"u}r R100 einer weiteren Optimierung bed{\"u}rfen. Eine Temperierung von R100 im Injektor auf 50-60 °C sowie eine Kompensation der Einspritzmenge in Abh{\"a}ngigkeit von der Kraftstofftemperatur sind m{\"o}gliche Verbesserungsmaßnahmen. Zudem kann durch einen fr{\"u}heren Einspritzbeginn von R100 das Verbrennungsverhalten angepasst werden. Die Motorpr{\"u}fstandsuntersuchungen best{\"a}tigen qualitativ die Erkenntnisse die mit dem hydraulischen Druckanstiegsanalysator (HDA), der Hochdruck-Hochtemperatur-Kammer (HDHT-Kammer) und der Konstantvolumenbrennkammer gewonnen wurden. Weitere Untersuchungen sind notwendig, um die Ergebnisse auf einen baugleichen, in einer mobilen Arbeitsmaschine eingebauten Motor zu transferieren, damit Informationen zur Dauerhaltbarkeit unter realen Bedingungen erhalten werden k{\"o}nnen. Weiterf{\"u}hrende Forschungsarbeiten sind im Bereich der Betriebsphasen des Motorkaltstarts und Leerlaufs mit Raps{\"o}lkraftstoff n{\"o}tig, um einen dauerhaft st{\"o}rungsfreien Betrieb in diesen Betriebsphasen zu erreichen. Die erzielten Erkenntnisse deuten darauf hin, dass hier noch viel Verbesserungspotenzial vorhanden ist.}, subject = {Biokraftstoff}, language = {de} } @misc{OetjenRiegerRabletal., author = {Oetjen, Arne and Rieger, Anna and Rabl, Hans-Peter and van de Par, Steven}, title = {The role of dissonance in the sound quality perception for electric vehicles}, series = {The Journal of the Acoustical Society of America}, volume = {148}, journal = {The Journal of the Acoustical Society of America}, number = {4}, publisher = {Acoustical Society of America}, doi = {10.1121/1.5147356}, abstract = {Tonal components can be regarded as one of the most relevant components for interior sound quality of electric vehicles, especially at low speeds. Sources for these tones are for example the vehicles' drivetrains but also other technical components. Depending on the driving conditions, due to the interaction of various dominant sources, audible tone complexes can occur. Similar to musical intervals, the different frequency ratios within these complexes can result in consonant or dissonant sensations. The strength of this sensation does not only depend on the frequency relation of the tones but also on their relative levels. In this study, different musical intervals were subjectively rated in terms of their specific consonant or dissonant character. Using an adaptive procedure, sound pairs, each consisting of a two-tone signal, where adjusted to equal dissonance by varying the level of the second tone of one of the two-tone signals. Using the same paradigm, also pairs of equal vehicle sound quality were obtained. With these results, it is possible to quantify dissonance, and theinfluence of dissonance on sound quality expressed in terms of level differences of two-tone signals. These results can help to make the concept of dissonance more useful for sound-engineering applications.}, language = {en} } @incollection{WalterSchwanzerHagenetal., author = {Walter, Stefanie and Schwanzer, Peter and Hagen, Gunter and Haft, Gerhard and Dietrich, Markus and Rabl, Hans-Peter and Moos, Ralf}, title = {Hochfrequenzsensorik zur direkten Beladungserkennung von Benzinpartikelfiltern}, series = {Automobil-Sensorik 3}, booktitle = {Automobil-Sensorik 3}, editor = {Tille, Thomas}, publisher = {Springer Vieweg}, address = {Berlin}, isbn = {978-3-662-61259-0}, doi = {10.1007/978-3-662-61260-6_7}, pages = {185 -- 208}, abstract = {In Folge der Versch{\"a}rfung der gesetzlichen Abgasnormen wurden f{\"u}r direkt-einspritzende Benzinmotoren Partikelfilter notwendig. Zur Beladungs{\"u}berwachung k{\"o}nnen aufgrund stark unterschiedlicher Rahmenbedingungen die aus Dieselmotoren bekannten Systeme, wie dem Differenzdrucksensor, nur eingeschr{\"a}nkt {\"u}bernommen werden. Ein hochfrequenzbasiertes Verfahren koppelt mittels Antennen elektromagnetische Wellen in das Filtergeh{\"a}use ein, deren Ausbreitungsverhalten durch die dielektrischen Eigenschaften des eingelagerten Rußes beeinflusst wird. Hierdurch kann bei Auswertung von Transmissionsd{\"a}mpfung oder Resonanzfrequenzen die Rußbeladung direkt detektiert werden.}, language = {en} } @misc{SchwanzerMieslingerRabletal., author = {Schwanzer, Peter and Mieslinger, Johann and Rabl, Hans-Peter and Dietrich, Markus and Haft, Gerhard and Walter, Stefanie and Hagen, Gunter and Moos, Ralf and Gaderer, Matthias}, title = {Monitoring of a Particulate Filter for Gasoline Direct Injection Engines with a Radio-Frequency-Sensor}, series = {11th International Exhaust Gas and Particulate Emissions Forum, 3.-4.3.2020, Ludwigsburg, Germany}, journal = {11th International Exhaust Gas and Particulate Emissions Forum, 3.-4.3.2020, Ludwigsburg, Germany}, abstract = {In order to comply with future emission regulations, the use of particulate filters in vehicles with direct injection gasoline engines is essential. The current amount of soot and ash in the filter is calculated by a soot load model in the electronic control unit in combination with a differential pressure sensor determining the pressure drop over the particulate filter. Active regeneration is initiated if the calculated amount of soot or the measured differential pressure is too high. This is associated with additional fuel consumption. An on-board diagnosis for the particulate filter is currently not part of the Euro 6d emission standard. For future exhaust emission standards, on-board diagnosis or active monitoring of the particulate filter is conceivable. One of the benefits of monitoring is the fact that unnecessary active regenerations can be avoided. As a result, there is no additional fuel consumption due to misinterpretations of the amount of soot in the filter. For active monitoring of the particulate filter, a radiofrequency (RF-) sensor, that detects the soot loading of the filter with electromagnetic waves directly, can be used. Such a system has the advantage that by utilizing the filter as a sensor more precise information about the current state of the filter, e.g. a possible damage, can be provided. Worst-case considerations of filter damages, tested at an engine test bench show the advantages which are entailed by a system like that. By means of partial regeneration of the particulate filter it is demonstrated how the remaining amount of soot in the filter can be detected in a better way in comparison to the differential pressure sensor by using the RF-sensor.}, language = {en} } @article{Briem, author = {Briem, Ulrich}, title = {Die neue VDI 2500 : Faserseilwissen kompakt}, series = {Logistik f{\"u}r Unternehmen}, journal = {Logistik f{\"u}r Unternehmen}, number = {11-12}, pages = {36 -- 37}, abstract = {Die Richtlinie VDI 2500 „Faserseile" hat 1990 erstmals zusammenfassend den Stand der Technik auf dem Gebiet der Faserseile dargestellt und wertvolle Infor-mationen {\"u}ber Aufbau, Auswahl, Konfek-tionierung und {\"U}berwachung von Faser-seilen gegeben. Die jetzt erscheinende zweite Auflage enth{\"a}lt eine Vielzahl wichtiger technischer Neuerungen f{\"u}r die Praxis. Zu nennen sind hier die hochfesten Fasern und deren Beschichtung sowie die erstmals systematisch aufgef{\"u}hrten Sei-lendverbindungen und ein Ausblick auf die zuk{\"u}nftig bedeutsamen sogenannten Hybridseile. Eine Checkliste hilft bei der richtigen Auswahl und Bemessung von Faserseilen. Bei den Normen wurde - soweit m{\"o}glich - auf europ{\"a}ische Normen verwiesen.}, language = {de} } @article{Briem, author = {Briem, Ulrich}, title = {Umlaufbiegewechselzahl von verdichteten Seildr{\"a}hten}, series = {Draht}, journal = {Draht}, number = {6}, pages = {14 -- 15}, language = {de} }