TY - CHAP A1 - Rauch, Johannes A1 - Brückl, Oliver A1 - Engel, Bernd ED - Schulz, Detlef T1 - Analysis and optimization of the steady state voltage deviation demand for reactive power planning using installed reactive power sources T2 - NEIS 2022; Conference on Sustainable Energy Supply and Energy Storage Systems, 26-27 September 2022, Hamburg N2 - 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. KW - Reactive Power KW - Reactiver Power Planning KW - Voltage Control KW - Optimal Power Flow KW - Differential Evolution Y1 - 2022 UR - https://ieeexplore.ieee.org/document/10048083 SN - 978-3-8007-5983-5 SN - 2510-6902 SP - 175 EP - 182 PB - VDE-Verlag CY - Berlin ER - TY - CHAP A1 - Schweiberer, Philipp A1 - Rauch, Johannes A1 - Brückl, Oliver ED - Schulz, Detlef T1 - 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 T2 - NEIS 2022; Conference on Sustainable Energy Supply and Energy Storage Systems, 26-27 September 2022, Hamburg N2 - 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. KW - Reactive Power KW - Reactive Power Potentials KW - Industrial plant KW - Voltage Stability KW - Long term analysis Y1 - 2022 UR - https://ieeexplore.ieee.org/document/10048065 SN - 978-3-8007-5983-5 SN - 2510-6902 SP - 51 EP - 56 PB - VDE-Verlag CY - Berlin ER - TY - RPRT A1 - Brixner, Luis A1 - Gnerlich, Patrick A1 - Jakob, Jonas A1 - Kiener, Johannes A1 - Oberländer, Jonas A1 - Plößl, Moritz A1 - Schächinger, Stefan A1 - Stelz, Raphael A1 - Wartner, Felix ED - Fuhrmann, Thomas ED - Niemetz, Michael ED - Reindl, Andrea T1 - FMS-Berichte Wintersemester 2023/24 BT - Seminar zu aktuellen Themen der Elektro- und Informationstechnik N2 - Dieser Bericht entstand ursprünglich auf Initiative der Studierenden des damals neuen Masterstudiengangs „Elektro- und Informationstechnik (MEI)“ an der OTH Regensburg, die an der Pflichtlehrveranstaltung „Forschungsmethoden und Seminar (FMS)“ im Wintersemester 2020/21 teilnahmen. Diese Lehrveranstaltung hat das Ziel, systematisch an das wissenschaftliche Arbeiten, speziell die Wissenschaftskommunikation, heranzuführen. Daher ist im Laufe der Veranstaltung geeignete Literatur zu einem individuellen Thema zu recherchieren, sind Veröffentlichungen auf ihre Relevanz hin zu beurteilen und letztendlich gilt es eine eigene Ausarbeitung basierend auf der Literaturrecherche zu erstellen und diese in einem Vortrag zu präsentieren. Parallel dazu wird im Theorieteil die entsprechende Hinführung zu den verschiedenen Elementen der Wissenschaftskommunikation vermittelt: • Bedeutung der Wissenschaftskommunikation für die Arbeit der Ingenieure in Forschung und Entwicklung • Literaturrecherche, Suchmaschinen, Sichtung und Analyse vorhandener Publikationen, Bewertung der Qualität aufgefundener Fachliteratur, Auswahl geeigneter Materialien für die eigene Arbeit • Aufbereitung und Darstellung der recherchierten technischer Inhalte in Form einer seitenanzahlbegrenzten wissenschaftlichen Ausarbeitung • Einhalten formaler Randbedingungen bzgl. Strukturierung, einschl. Bildnachweise und Zitationsstile • Peer-review-Prozess bei wertschätzender Beurteilung der Leistung anderer • Publikumsangepasstes Aufbereiten komplexer fachlicher Inhalte mit hochschulöffentlicher Präsentation der Ergebnisse • Führen mündlicher wissenschaftlicher Diskurse Die präsentierten Themen beruhen nicht auf eigener Forschungstätigkeit, sondern sind als einführende Reviewartikel zum jeweiligen vorgegebenen technischen oder gesellschaftspolitischen Forschungsthema zu verstehen. T3 - Forschungsmethoden-Seminar - 7 KW - Elektrotechnik KW - Informationstechnik KW - Energietechnik KW - Literaturrecherche Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-77796 IS - 1 CY - Regensburg ER - TY - RPRT A1 - Blößer, Julia A1 - Branilovic, Fabio A1 - Michael, Bretz A1 - Ebner, Andreas A1 - Gleich, Ralf A1 - Inderst, Christian A1 - Kopp, Lorenz A1 - Müller, Markus A1 - Schächiner, Michael A1 - von Beerfelde, Rebekka ED - Fuhrmann, Thomas ED - Niemetz, Michael ED - Reindl, Andrea T1 - FMS-Berichte Sommersemester 2024 BT - Seminar zu aktuellen Themen der Elektro- und Informationstechnik T2 - FMS-Berichte Sommersemester 2024 N2 - Dieser Bericht entstand ursprünglich auf Initiative der Studierenden des damals neuen Masterstudiengangs „Elektro- und Informationstechnik (MEI)“ an der OTH Regensburg, die an der Pflichtlehrveranstaltung „Forschungsmethoden und Seminar (FMS)“ im Wintersemester 2020/21 teilnahmen. Diese Lehrveranstaltung hat das Ziel, systematisch an das wissenschaftliche Arbeiten, speziell die Wissenschaftskommunikation, heranzuführen. Daher ist im Laufe der Veranstaltung geeignete Literatur zu einem individuellen Thema zu recherchieren, sind Veröffentlichungen auf ihre Relevanz hin zu beurteilen und letztendlich gilt es eine eigene Ausarbeitung basierend auf der Literaturrecherche zu erstellen und diese in einem Vortrag zu präsentieren. Parallel dazu wird im Theorieteil die entsprechende Hinführung zu den verschiedenen Elementen der Wissenschaftskommunikation vermittelt: • Bedeutung der Wissenschaftskommunikation für die Arbeit der Ingenieure in Forschung und Entwicklung • Literaturrecherche, Suchmaschinen, Sichtung und Analyse vorhandener Publikationen, Bewertung der Qualität aufgefundener Fachliteratur, Auswahl geeigneter Materialien für die eigene Arbeit • Aufbereitung und Darstellung der recherchierten technischer Inhalte in Form einer seitenanzahlbegrenzten wissenschaftlichen Ausarbeitung • Einhalten formaler Randbedingungen bzgl. Strukturierung, einschl. Bildnachweise und Zitationsstile • Peer-review-Prozess bei wertschätzender Beurteilung der Leistung anderer • Publikumsangepasstes Aufbereiten komplexer fachlicher Inhalte mit hochschulöffentlicher Präsentation der Ergebnisse • Führen mündlicher wissenschaftlicher Diskurse Die präsentierten Themen beruhen nicht auf eigener Forschungstätigkeit, sondern sind als einführende Reviewartikel zum jeweiligen vorgegebenen technischen oder gesellschaftspolitischen Forschungsthema zu verstehen. T3 - Forschungsmethoden-Seminar - 8 KW - Elektrotechnik KW - Informationstechnik KW - Energietechnik KW - Literaturrecherche Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-77801 IS - 1 CY - Regensburg ER - TY - RPRT A1 - Rank, Daniel A1 - Heberl, Michael A1 - Sterner, Michael T1 - Die CO2-Bilanz der OTH [Ostbayerischen Technische Hochschule Regenburg] BT - Tool für Hochschulen und Firmen Y1 - 2020 UR - https://sae58cb7e2208a3d2.jimcontent.com/download/version/1613400473/module/9240277976/name/1. Sitzung AG_Präsentation Prof. Sterner-1.pdf ER - TY - JOUR A1 - Chatzitakis, Paris A1 - Safarov, Javid A1 - Opferkuch, Frank A1 - Dawoud, Belal T1 - Experimental investigation of an absorption heat pump with organic working pairs JF - Applied Thermal Engineering N2 - As part of a systematic approach towards the search for alternative absorption heat pump (AHP) working pairs that could potentially provide comparable performance to conventional ones, a previous work performed a detailed theoretical cycle analysis and simulation that revealed concrete correlations between key working fluid thermophysical properties and AHP performance indicators. Following this work, targeted combinations of two organic refrigerants, 2,2,2-trifluoroethanol (TFE) and 2,2,3,3,3-pentafluoropropanol (5FP) and two organic absorbents, 1,3-dimethyl-2-imidazolidinone (DMI) and 2-pyrrolidone (PYR) were tested in a prototype 5 kW AHP, based on a highly compact plate heat exchanger design, which has been previously introduced. The purpose of this effort was to test the findings of the previous work with experimental measurements. The working pair combinations were also subjected to vapor liquid equilibrium (VLE) and viscosity measurements, in order to determine reliable activity coefficient and improve the accuracy of the simulations. The experimental performance data agree well with the COP simulations and show to be consistent with the conclusions derived from the previous theoretical work. KW - Absorption heat pump KW - Coefficient of performance KW - FLUID KW - MIXTURES KW - Organic working pairs KW - Specific solution circulation Y1 - 2019 U6 - https://doi.org/10.1016/j.applthermaleng.2019.114311 VL - 163 IS - December PB - Elsevier ER - TY - JOUR A1 - Hansen, B. A1 - Hoebler, Michael A1 - Purr, Stephan A1 - Meinhardt, J. A1 - Merklein, Marion T1 - Basics for inline measurement of tribological conditions in series production of car body parts JF - IOP Conference Series: Materials Science and Engineering N2 - The quality of car body parts in series production is strongly dependent on the tribological behavior. Fluctuating material properties such as the sheet roughness and the amount of lubricant have an influence on the forming process. On the basis of large amounts of data it is possible to investigate the friction behavior in series production and to make process adjustments if required. Therefore, inline measurement systems have a great potential to detect the sheet roughness during the cutting process of blanks in the coil line. Furthermore, contactless systems are advantageous as they do not damage the surface. Nevertheless, the optical measuring is influenced by the lubricant layer on top of the surface. Therefore, the previously unknown impact of the lubricant on the measuring result is investigated. Within this study, stationary optical roughness measurements have been conducted using different amounts of lubricant on hot-dip galvanized EDT steel. The results demonstrate the influence of different amounts of lubricant on the sheet roughness measurement. Hence, it is possible to correct the inline measuring results and gain knowledge of fluctuating surface roughness. In addition, strip drawing test has been carried out to investigate the effect of fluctuating tribological conditions. Y1 - 2019 U6 - https://doi.org/10.1088/1757-899x/651/1/012050 VL - 651 PB - IOP Publishing ER - TY - CHAP A1 - Bresinsky, Markus A1 - Reusner, Florian T1 - GLOBE – Learn and Innovate Digitization by a Virtual Collaboration Exercise and Living Lab T2 - Interactivity, Game Creation, Design, Learning, and Innovation. 6th International Conference, ArtsIT 2017, and Second International Conference, DLI 2017, Heraklion, Crete, Greece, October 30–31, 2017, Proceedings N2 - This paper presents an advanced interactive learning platform .dot that implements the GLOBE exercise, using innovative information and communication technologies to enhance learning and development of management and leadership skills in a complex organizational setting. GLOBE on the one hand focuses on competences around ICT and virtual collaboration, and on the other hand on digital transformation, technologies and tools at higher education institutions. By this applied science, learning and developing on the real-world platform, analysis and drive of digital innovation and transformation can be fostered. The main goal is to co-create knowledge and solutions in the following focused subjects: Management and leadership of multidisciplinary, multinational and multicultural virtual and real collaboration in a complex organizational environment. GLOBE uses real world scenarios (e.g. United Nations mission) and involves real world actors. This comprehensive educational approach should enhance learning techniques and leverage learning progress with hands-on experiences and applied science in the context of ICT and virtual collaboration, and the embodied dynamics of behavior to support innovation and development. KW - Digitization KW - Experiential learning KW - Human factors KW - ICT KW - Interactive and collaborative learning KW - Living Lab KW - Open innovation KW - Problem-based learning KW - Virtual collaboration Y1 - 2018 U6 - https://doi.org/10.1007/978-3-319-76908-0_26 SP - 273 EP - 281 PB - Springer Nature ER - TY - JOUR A1 - Hofrichter, Andreas A1 - Rank, Daniel A1 - Heberl, Michael A1 - Sterner, Michael T1 - Determination of the optimal power ratio between electrolysis and renewable energy to investigate the effects on the hydrogen production costs JF - International Journal of Hydrogen Energy N2 - 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. Y1 - 2023 U6 - https://doi.org/10.1016/j.ijhydene.2022.09.263 SN - 0360-3199 N1 - Corresponding author: Michael Heberl N1 - Corrigendum to “Determination of the optimal power ratio between electrolysis and renewable energy to investigate the effects on the hydrogen production costs” [Int J Hydrogen Energy 48 (5) (2023) 1651–1663] - https://doi.org/10.1016/j.ijhydene.2023.03.128 VL - 48 IS - 5 SP - 1651 EP - 1663 PB - Elsevier ER - TY - CHAP A1 - Gärtner, Sebastian A1 - Rank, Daniel A1 - Heberl, Michael A1 - Gaderer, Matthias A1 - Sterner, Michael T1 - Integration of Power-To-Methane into Glass Melting Processes T2 - Proceedings of the International Renewable Energy Storage Conference (IRES 2022) N2 - 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. KW - Power-to-Gas KW - Methanation KW - Glass Melting KW - Glass Industry KW - Decarbonisation Y1 - 2023 U6 - https://doi.org/10.2991/978-94-6463-156-2_12 SN - 2589-4943 VL - 16 SP - 147 EP - 161 PB - Atlantis Press ER - TY - CHAP A1 - Tremmel, Florian A1 - Nagler, Oliver A1 - Kutter, Christoph A1 - Holmer, Rainer T1 - Smart Cantilever Probe with Integrated Force and Acoustic Emission Sensor T2 - 2023 IEEE SENSORS, Vienna, Austria, 10/29/2023 - 11/1/2023 N2 - 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. KW - Acoustic emission testing KW - piezoelectric sensor KW - strain gauge KW - operational amplifier circuit Y1 - 2023 SN - 979-8-3503-0387-2 U6 - https://doi.org/10.1109/SENSORS56945.2023.10325021 SP - 1 EP - 4 PB - IEEE ER - TY - INPR A1 - Heberl, Michael A1 - Withelm, Christian A1 - Kaul, Anja A1 - Rank, Daniel A1 - Sterner, Michael T1 - Prospective Life Cycle Assessment of Biological Methanation in a Trickle-Bed Pilot Plant and a Potential Scale-Up N2 - 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. Y1 - 2023 U6 - https://doi.org/10.2139/ssrn.4635066 N1 - Der Aufsatz wurde peer-reviewd veröffentlich und ist ebenfalls in diesem Repositorium verzeichnet unter: https://opus4.kobv.de/opus4-oth-regensburg/frontdoor/index/index/docId/7349 PB - SSRN ER - TY - CHAP A1 - Rill, Georg ED - Apetaur, Milan T1 - Vehicle Dynamics in Real-Time Simulation T2 - The dynamics of vehicles on roads and on tracks N2 - This paper presents some ideas on a new concept, named COMPACT (Computer Simulation of Passenger Cars and Trucks). COMPACT was developed for the mathematical description of vehicles in all driving situations. As COMPACT is completely adopted to the particular problems in road vehicle dynamics, it results in a computer code where execution time is minimized. Thus, even real-time application at the Daimler-Benz driving simulator is possible. Previous Chapter Next Chapter Y1 - 2021 SN - 9781003210894 U6 - https://doi.org/10.1201/9781003210894-40 SP - 337 EP - 347 PB - CRC Press CY - Boca Raton ER - TY - INPR A1 - Meisinger, Alexander A1 - Hofrichter, Andreas A1 - Bauer, Franz A1 - Sterner, Michael T1 - Unlocking Potential Energy Partnerships in Europe: a Case Study on the Way to a Franco-German Energy Transition N2 - Global warming is already causing global destabilization. Geopolitical challenges fuel this instability and highlight the need for trusted energy partnerships to ensure energy security. To limit global warming and increase energy security, it is essential to take joint action on an international and global scale. The European Green Deal contributes to this. However, specific national actions are still needed. This research presents a way forward for a Franco-German energy transition and unlocks the potential of energy partnerships within Europe, using a cost-based, sector-coupled optimization model. Both countries are coupled via an isolated country optimization approach. Thus, the focus is on the development of each national energy system. The results highlight the increase of energy security in line with the European Green Deal. The main pillars of the energy transition are solar energy (32- 33%), wind energy (25-38%) and biogenic energy sources (13-27%). Nuclear power is being phased out in Germany and France. The results show that a Franco-German energy partnership has great potential. Overall, France can cost-effectively cover 25% of Germany’s hydrogen import needs (122 TWh) in 2050. At the same time, France can also benefit from the energy partnership in terms of economic growth and joint action to mitigate climate crisis. KW - Decarbonization KW - Energy partnership KW - Energy system modelling KW - Energy transition KW - European Green Deal KW - Power-to-X Y1 - 2025 U6 - https://doi.org/10.2139/ssrn.5251699 PB - SSRN ER - TY - JOUR A1 - Romeis, Dirk A1 - Kostrov, Sergei A. A1 - Kramarenko, Elena Yu A1 - Stepanov, Gennady V. A1 - Shamonin (Chamonine), Mikhail A1 - Saphiannikova, Marina T1 - Magnetic-field-induced stress in confined magnetoactive elastomers JF - Soft Matter N2 - We present a theoretical approach for calculating the state of stress induced by a uniform magnetic field in confined magnetoactive elastomers of arbitrary shape. The theory explicitly includes the magnetic field generated by magnetizable spherical inclusions in the sample interior assuming a non-linear magnetization behavior. The initial spatial distribution of particles and its change in an external magnetic field are considered. This is achieved by the introduction of an effective demagnetizing factor where both the sample shape and the material microstructure are taken into account. Theoretical predictions are fitted to the stress data measured using a specifically designed experimental setup. It is shown that the theory enables the quantification of the effect of material microstructure upon introducing a specific microstructural factor and its derivative with respect to the extensional strain in the undeformed state. The experimentally observed differences between isotropic and anisotropic samples, compliant and stiff elastomer matrices are explained. Y1 - 2020 U6 - https://doi.org/10.1039/D0SM01337D VL - 16 IS - 39 SP - 9047 EP - 9058 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Snarskii, Andrei A. A1 - Shamonin (Chamonine), Mikhail A1 - Yuskevich, Pavel A1 - Savelev, Dmitrii V. A1 - Belyaeva, Inna A. T1 - Induced anisotropy in composite materials with reconfigurable microstructure: Effective medium model with movable percolation threshold JF - Physica A: Statistical Mechanics and its Applications N2 - In composite materials, with field-dependent restructuring of the filler material (changes in the mutual arrangement of inclusions), the presence of an external magnetic field induces anisotropy of the dielectric properties, even if the composite is isotropic in the absence of an external field. A modified effective medium approximation is proposed for the calculation of the components of effective permittivity within a class of composites with reconfigurable microstructure, where both phases (the filler and the matrix) are isotropic and the inclusions have spherical shape. The effective physical properties are calculated in the parallel and perpendicular directions to an applied field. The appearance of the anisotropy of the permittivity is simulated by the introduction of two not-equal, possibly variable (field-dependent) percolation thresholds. The implications, of the proposed theoretical approach, are demonstrated for the case of the dielectric properties of magnetoactive elastomers (MAEs). In MAEs with soft polymer matrices, the mutual arrangement of micrometer-sized magnetic inclusions can significantly change in an applied magnetic field. A reasonable agreement between theory and experiment at a measurement frequency of 1 kHz is found, and is improved in comparison to the previous models. The components of the effective permittivity tensor, characterizing the dielectric properties along the direction of the applied magnetic field and in the orthogonal direction, grow with an increasing field. This growth is more pronounced for the permittivity component in the field direction. The possible extensions of the theoretical model and future directions of research are discussed. The presented theoretical approach can be useful for the application-driven development of a number of smart materials, in particular electro- and magnetorheological gels, elastomers and fluids. KW - Effective medium theory KW - Magnetoactive elastomer KW - Percolation threshold KW - Anisotropy KW - Effective permittivity KW - Random heterogeneous medium Y1 - 2020 U6 - https://doi.org/10.1016/j.physa.2020.125170 VL - 560 IS - December PB - Elsevier ER - TY - JOUR A1 - Savelev, Dmitrii V. A1 - Belyaeva, Inna A. A1 - Chashin, Dmitri V. A1 - Fetisov, Leonid Y. A1 - Romeis, Dirk A1 - Kettl, Wolfgang A1 - Kramarenko, Elena Yu A1 - Saphiannikova, Marina A1 - Stepanov, Gennady V. A1 - Shamonin (Chamonine), Mikhail T1 - Giant extensional strain of magnetoactive elastomeric cylinders in uniform magnetic fields JF - Materials N2 - Elongations of magnetoactive elastomers (MAEs) under ascending–descending uniform magnetic fields were studied experimentally using a laboratory apparatus specifically designed to measure large extensional strains (up to 20%) in compliant MAEs. In the literature, such a phenomenon is usually denoted as giant magnetostriction. The synthesized cylindrical MAE samples were based on polydimethylsiloxane matrices filled with micrometer-sized particles of carbonyl iron. The impact of both the macroscopic shape factor of the samples and their magneto-mechanical characteristics were evaluated. For this purpose, the aspect ratio of the MAE cylindrical samples, the concentration of magnetic particles in MAEs and the effective shear modulus were systematically varied. It was shown that the magnetically induced elongation of MAE cylinders in the maximum magnetic field of about 400 kA/m, applied along the cylinder axis, grew with the increasing aspect ratio. The effect of the sample composition is discussed in terms of magnetic filler rearrangements in magnetic fields and the observed experimental tendencies are rationalized by simple theoretical estimates. The obtained results can be used for the design of new smart materials with magnetic-field-controlled deformation properties, e.g., for soft robotics. KW - magnetostriction KW - magnetoactive elastomer KW - extensional strain KW - hysteresis KW - magnetomechanical effect KW - magnetodeformation Y1 - 2020 U6 - https://doi.org/10.3390/ma13153297 SN - 1996-1944 N1 - Corresponding author: Mikhail Shamonin VL - 13 IS - 15 SP - 1 EP - 17 PB - MDPI CY - Basel ER - TY - JOUR A1 - Savelev, Dmitrii V. A1 - Fetisov, Leonid Y. A1 - Chashin, Dmitri V. A1 - Fetisov, Yuri K. A1 - Khon, Anastasia A1 - Shamonin (Chamonine), Mikhail T1 - Effects of ferromagnetic-material thickness on magnetoelectric voltage transformation in a multiferroic heterostructure JF - Smart Materials and Structures N2 - 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. KW - magnetoelectric effect KW - magnetostriction KW - multiferroic heterostructure KW - piezoelectric effect KW - voltage transformer Y1 - 2021 U6 - https://doi.org/10.1088/1361-665X/abf6c0 VL - 30 IS - 6 PB - IOP PUBLISHING ER - TY - JOUR A1 - Savelev, Dmitrii V. A1 - Belyaeva, Inna A. A1 - Chashin, Dmitri V. A1 - Fetisov, Leonid Y. A1 - Shamonin (Chamonine), Mikhail T1 - Large Wiedemann effect in a magnetoactive elastomer JF - Journal of Magnetism and Magnetic Materials N2 - Large twists of a soft tube (hollow cylinder) in helical magnetic fields are presented for the first time. Such a phenomenon is usually denoted as the Wiedemann effect. The tube is fabricated from a soft magnetoactive elastomer material with the shear modulus of about 56 kPa. The composite material comprises 80 mass% of micrometer-sized iron particles embedded into a polydimethylsiloxane matrix. The circular magnetic field is generated by an electric current in a straight wire passing through the inner hole of the tube. The maximum value of approximately 350″/cm is observed in a longitudinal magnetic field of a few kA/m overlapped with a circumferential magnetic field of about 1.4 kA/m on the surface of the inner hole. A pronounced hysteresis in the dependence of the Wiedemann effect on the circular magnetic field is found. The ways to enhance the Wiedemann twist in magnetoactive elastomers are discussed. The observed large effect is promising for application in magnetic-field controlled torsional actuators, in particular for soft robotics. Y1 - 2020 U6 - https://doi.org/10.1016/j.jmmm.2020.166969 VL - 511 IS - October PB - Elsevier ER - TY - JOUR A1 - Savelev, Dmitrii V. A1 - Fetisov, Leonid Y. A1 - Chashin, Dmitri V. A1 - Shabin, P. A. A1 - Vyunik, D. A. A1 - Fedulov, Feodor A1 - Kettl, Wolfgang A1 - Shamonin (Chamonine), Mikhail T1 - Method of Measuring Deformations of Magnetoactive Elastomers under the Action of Magnetic Fields JF - Russian Technological Journal Y1 - 2019 U6 - https://doi.org/10.32362/2500-316x-2019-7-4-81-91 VL - 7 IS - 4 SP - 81 EP - 91 ER - TY - CHAP A1 - Mühlbauer, Christian A1 - Rabl, Hans-Peter A1 - Rottengruber, Hermann ED - Siebenpfeiffer, Wolfgang T1 - Development of a Methodology for Acoustic Analysis and Optimization of Mechatronic Fuel Injection Systems T2 - Automotive Acoustics Conference 2019: Proceedings, 5. Internationale ATZ-Fachtagung Fahrzeugakustik N2 - To identify the sound quality of fuel injection systems as a frontloading measure, a system test bench has been developed that simulates the structure and airborne noise emission. The setup of the system test bench includes an assembly of the acoustical relevant engine parts and an encapsulated drive for the high-pressure pump. A specific control unit enables a high variability for the operation strategy of the injection system. The focus of this study is on the development of a methodology to analyze and optimize the sound quality of gasoline direct injectors in critical operation points by suitable active means. For this, the injection parameters in engine idle have been identified and subsequently transferred to the system test bench. Additionally, the injection parameters have been optimized acoustically and the impacts on the key functions regarding injection rating and shot-to-shot scattering of the injected fuel mass are discussed. Y1 - 2020 SN - 978-3-658-27668-3 U6 - https://doi.org/10.1007/978-3-658-27669-0_15 SP - 211 EP - 225 PB - Springer Vieweg CY - Wiesbaden ER - TY - GEN A1 - Pershina, K. V. A1 - Savelev, Dmitrii V. A1 - Glavan, Gašper A1 - Chashin, Dmitri V. A1 - Belyaeva, Inna A. A1 - Fetisov, Leonid Y. A1 - Shamonin (Chamonine), Mikhail T1 - The voltage response of a structure comprising a magnetoactive-elastomer cylinder and a piezoelectric material to magnetic field step excitations T2 - The 4th International Baltic Conference on Magnetism (IBCM 2021) : Svetlogorsk, Russia August 29 - September 2, 2021 : Book of Abstracts Y1 - 2021 UR - http://smba.science/wp-content/uploads/2021/10/IBCM-2021-Book-of-Abstracts-5.pdf SP - 182 PB - Immanuel Kant Baltic Federal University, Kaliningrad, Russia ER - TY - BOOK A1 - Rill, Georg A1 - Schaeffer, Thomas T1 - Grundlagen und Methodik der Mehrkörpersimulation N2 - Dieses Lehrbuch stellt die Methoden der Mehrkörpersimulation anschaulich dar und erläutert an einfachen Beispielen die Vor- und Nachteile bei der praktischen Anwendung. In den Text integrierte Matlab-Skripte und -Funktionen verdeutlichen die einzelnen Methoden. Die Modellbildung, die mathematische Beschreibung und die numerische Simulation von Systemen starrer Körper bilden dabei die Schwerpunkte. Konkrete Beispiele beinhalten die Eigendynamik eines Traktors mit Vorderachsfederung, das Hubschrauberrotorblatt sowie eine Pkw- Vorderachse. Die entsprechenden Matlab-Skripte und Lösungen zu den Übungsaufgaben können auf der Springer-Homepage beim Buch heruntergeladen werden. Neu aufgenommen wurden SparseMatrix Operationen sowie ein Beispiel zu einfach geschlossenen kinematischen Schleifen. Y1 - 2017 SN - 978-3-658-16008-1 U6 - https://doi.org/10.1007/978-3-658-16009-8 PB - Springer CY - Wiesbaden ET - 3. Aufl. ER - TY - BOOK A1 - Rill, Georg A1 - Schaeffer, Thomas T1 - Grundlagen und Methodik der Mehrkörpersimulation : Vertieft in Matlab-Beispielen, Übungen und Anwendungen N2 - Dieses Lehrbuch vermittelt nicht nur Grundlagen, sondern stellt auch die Methoden der Mehrkörpersimulation anschaulich dar und erläutert an einfachen Beispielen die Vor- und Nachteile bei der praktischen Anwendung. In den Text integrierte Matlab-Skripte und -Funktionen verdeutlichen die einzelnen Methoden und ermöglichen es, Aufwand und Problematik bei der Umsetzung der Theorie innerhalb von Simulationsprogrammen einzuschätzen. Die Modellbildung, die mathematische Beschreibung und die numerische Simulation von Systemen starrer Körper bilden dabei die Schwerpunkte. Konkret behandelte Beispiele sind die Eigendynamik eines Traktors mit gefederter Vorderachse, das Rotorblatt eines Hubschraubers sowie die Vorderachse eines Pkws. Die entsprechenden Matlab-Skripte und Lösungen zu den Übungsaufgaben können auf der Springer-Homepage beim Buch heruntergeladen werden. Der Inhalt Dynamik des starren Körpers - Bewegungsgleichungen - Starre Körper mit elastischen und kinematischen Verbindungselementen - Integrationsverfahren - Rekursiver Algorithmus - Differential-Algebraische Gleichungen - Analyse von Mehrkörpersystemen - Anwendungs- und Übungsbeispiele aus der Technik Die Zielgruppen Studenten des Maschinenbaus, der Elektrotechnik und Mechatronik sowie der Biomechanik an Hochschulen und Universitäten Ingenieure in der Praxis, die sich mit Fragestellungen der Mehrkörpersimulation (MKS) befassen Entwickler aus der Kfz-Technik sowie Fachleute aus F+E Die Autoren Dr.-Ing. Georg Rill ist Professor mit den Lehrgebieten Technische Mechanik, Ingenieurinformatik, Fahrdynamik, Mehrkörperdynamik sowie Laborleiter Fahrdynamik. Dr.-Ing. Thomas Schaeffer ist Professor mit den Lehrgebieten Konstruktion, CAD, Maschinenelemente und Getriebetechnik, Mehrkörpersysteme und Bewegungstechnik sowie Laborleiter Mehrkörpersimulation, beide an der Ostbayerischen Technischen Hochschule (OTH) Regensburg. Y1 - 2014 U6 - https://doi.org/10.1007/978-3-658-06084-8 PB - Springer CY - Berlin ER - TY - JOUR A1 - Rill, Georg A1 - Schuderer, Matthias T1 - A Second-Order Dynamic Friction Model Compared to Commercial Stick–Slip Models JF - Modelling N2 - 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. KW - commercial stick–slip friction models KW - dynamic friction model KW - long-term stick KW - multibody dynamics Y1 - 2023 U6 - https://doi.org/10.3390/modelling4030021 SN - 2673-3951 N1 - Corresponding author: Georg Rill VL - 4 IS - 3 SP - 366 EP - 381 PB - MDPI ER - TY - GEN A1 - Sterner, Michael A1 - Schumm, Leon T1 - Netzpuffer – Speicher & Kraftwerke als virtuelle Leitungen für mehr Versorgungssicherheit und EE-Integration in Nord und Süd T2 - 7. Smart-Grid-Fachtagung WAGO, Hannover, 29. Sept. 2021 KW - Stromspeicher KW - Batterien KW - Netzpuffer KW - Stromnetz Y1 - 2021 ER - TY - RPRT A1 - Sterner, Michael A1 - Schumm, Leon A1 - Rank, Daniel A1 - Hofrichter, Andreas T1 - Intelligente Netzpuffer : Abschlussbericht (24.01.2021) KW - Stromspeicher KW - Batterien KW - Netzpuffer KW - Stromnetz Y1 - 2021 N1 - unveröffentlichter Abschlussbericht ER - TY - JOUR A1 - Walter, Stefanie A1 - Schwanzer, Peter A1 - Hagen, Gunter A1 - Rabl, Hans-Peter A1 - Dietrich, Markus A1 - Moos, Ralf T1 - Combined Ash and Soot Monitoring for Gasoline Particulate Filters Using a Radio-Frequency-Based Sensor JF - Emission Control Science and Technology N2 - 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. KW - Gasoline particulate flter KW - Radio-frequency KW - Soot mass determination KW - Ash detection Y1 - 2023 U6 - https://doi.org/10.1007/s40825-023-00235-y PB - Springer ER - TY - GEN A1 - Walter, Stefanie A1 - Schwanzer, Peter A1 - Hagen, Gunter A1 - Rabl, Hans-Peter A1 - Dietrich, Markus A1 - Moos, Ralf T1 - Combined Ash and Soot Monitoring in Gasoline Particulate Filters with a Radio-Frequency-Based Sensor T2 - SAE World Congress Experience, April 5-7, 2022, Detroit, Michigan, USA N2 - 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. Y1 - 2022 UR - https://eref.uni-bayreuth.de/id/eprint/69506 ER - TY - INPR A1 - Schumm, Leon A1 - Abdel-Khalek, Hazem A1 - Brown, Tom A1 - Ueckerdt, Falko A1 - Sterner, Michael A1 - Fioriti, Davide A1 - Parzen, Max T1 - The impact of temporal hydrogen regulation on hydrogen exporters and their domestic energy transition N2 - 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. KW - Energy Transition KW - Hydrogen regulation KW - Hydrogen export KW - Climate-neutral KW - Domestic prices KW - Hydrogen prices KW - Power-to-X Y1 - 2024 U6 - https://doi.org/10.21203/rs.3.rs-4285425/v1 N1 - Der Aufsatz wurde peer-reviewed veröffentlicht und ist ebenfalls in diesem Repositorium verzeichnet unter: https://opus4.kobv.de/opus4-oth-regensburg/8485 PB - Research Square Platform LLC ER - TY - JOUR A1 - Tremmel, Florian A1 - Nagler, Oliver A1 - Kutter, Christoph A1 - Holmer, Rainer T1 - Mechanical robustness analysis of semiconductors with a single needle probe card using acoustic emissions JF - e-Journal of Nondestructive Testing N2 - The combination of indentation testing and acoustic emission (AE) is widely used to analyze the fracture toughness of test substrates. In the manufacturing of semiconductor devices this material parameter also plays an important role. During the so-called wafer testing inside a wafer prober small probe tips are pressed onto the chip surface to check its performance. To prevent damaging the chip by that, the fracture toughness and load limit of it has to be defined in a prequalification step. This paper presents a test system that imitates the wafer testing process as close as possible and uses acoustic emission to detect appearing cracks and thereby also the load limit. The frontend of the test setup consists of a modular single needle probe card which can be placed in a wafer prober. Also, the indenter properties (tip diameter, stiffness, etc.) can be adjusted to the probe used later on during productive wafer testing to ensure realistic probing conditions. A piezoelectric sensor and a full strain gauge Wheatstone bridge are implemented close to the single indenter to measure the AEs and the applied contact force respectively. The signal-to-noise-ratios (SNRs) of both sensors are improved with an own analog amplifier module before recording them with an USB oscilloscope. A developed measurement software (LabVIEW) is used to adjust measurement parameters (trigger limit, record length, conversion factors, etc.) and automatically store and separate measurement data from different acoustic events and imprints. To evaluate the result files a second software tool (MATLAB) reads the files out and clusters the recorded events to separate crack signals from electrical and mechanical disturbances. With a prototype first test results are generated and the functionality and accuracy of the measurement concept is proven. KW - Acoustic Emission KW - Crack probability distribution KW - Fracture load limit KW - Wafer testing Y1 - 2024 U6 - https://doi.org/10.58286/30254 SN - 1435-4934 VL - 29 IS - 10 PB - NDT.net ER - TY - RPRT A1 - Volkenhoff, Tobias A1 - Gerstenberger, Marcus A1 - Breitbarth, Lutz A1 - Carstensen, Christian A1 - Dölger, Reiner A1 - Feldges, Michael A1 - Hegewald, Jessica A1 - Mutzbauer, Johannes A1 - Rose, Martin A1 - Schopf, Hans Jürgen A1 - Schroth, Max A1 - Schwietering, Christoph A1 - Seidel, Christian A1 - Sievers, Ariane A1 - Spangler, Matthias A1 - Trupat, Stefan A1 - Üstün, Ellen T1 - H NBA - Hinweise zum Einsatz von Netzbeeinflussungsanlagen KW - Verkehrstechnik KW - Netzbeeinflussungsanlagen KW - Verkehrsmanagement Y1 - 2025 SN - 978-3-86646-434-8 IS - 310/1 PB - FGSV CY - Köln ET - Ausgabe 2025 ER - TY - JOUR A1 - Schumm, Leon A1 - Brown, Tom A1 - Abdel-Khalek, Hazem A1 - Ueckerdt, Falko A1 - Sterner, Michael A1 - Fioriti, David A1 - Parzen, Max T1 - The impact of temporal hydrogen regulation on hydrogen exporters and their domestic energy transition JF - Nature Communications N2 - As global demand for green hydrogen rises, potential hydrogen exporters move into the spotlight. While exports can bring countries revenue, large-scale on-grid hydrogen electrolysis for export can profoundly impact 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-benefits of domestic carbon dioxide mitigation and hydrogen exports, whereby exports can reduce market-based costs for domestic electricity consumers while mitigation reduces costs for hydrogen exporters. However, increasing hydrogen exports in a fossil-dominated system can substantially raise market-based costs for domestic electricity consumers, but surprisingly, temporal matching of hydrogen production can lower these costs by up to 31% with minimal impact on exporters. Here, we show that 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. KW - Energy Transition KW - Hydrogen regulation Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-84857 N1 - Die Preprint-Version ist ebenfalls in diesem Repositorium verzeichnet unter: https://opus4.kobv.de/opus4-oth-regensburg/7272 VL - 16 PB - Nature CY - London ER - TY - RPRT A1 - Bhardwaj, Prakhar A1 - Hauer, Franziska A1 - Mücke, Vanessa A1 - Dotter, Caroline A1 - Haug, Sonja A1 - Weikl, Simone A1 - Weber, Karsten T1 - Recording and understanding multi- and intermodal mobility - a review N2 - The transition to sustainable mobility requires detailed knowledge of actual mobility behavior. Recording mobility behavior through conventional, aggregated, or retrospective survey methods (e.g., counting stations, travel diaries) may yield incomplete insights. In addition, these methods are often expensive, prone to error, or not scalable. The aim of this literature review is to provide a systematic overview of the current state of the literature on recording and analysis of individual mobility data and, based on this, to identify possible research gaps and potential. The exploratory literature review includes social science surveys on multi- and intermodal mobility behavior, as well as an overview of possible ways to analyze travel data. The focus of the latter is on identifying relevant data sources and methodological approaches for segmentation, identification of transport mode, and trip purpose determination. Results from recent studies show that sensor-based data collection alone is not sufficient to fully and accurately map mobility behavior. One possible solution is a “best-of-both-worlds” approach that combines passive, automatic mobility data collection via smartphone sensors with targeted user corrections and additions (“human-in-the-loop”) within an app. The literature review shows that this approach yields the best data quality. Combining mobility surveys with passive collection of mobility data provides a comprehensive, accurate, and complete overview of mobility behavior. KW - multimodal mobility KW - mobility Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-87427 CY - Regensburg ER - TY - GEN A1 - Rahim, Stefan A1 - Schumm, Leon T1 - Weather Data Cutouts for the Wasserstoffatlas (Hydrogen Map) [Data set] N2 - The cutouts are required to calculate the solar PV and wind onshore feed-in profiles of the Wasserstoffatlas. The provided cutouts are spatiotemporal subsets of the European weather data from the ECMWF ERA5 reanalysis dataset and the CMSAF SARAH-2 solar surface radiation dataset for the year 2013. They have been prepared by and are for use with the atlite tool (https://atlite.readthedocs.io/). ECMWF ERA5 Source: https://cds.climate.copernicus.eu/cdsapp#!/dataset/reanalysis-era5-single-levels?tab=overview Terms of Use: https://cds.climate.copernicus.eu/api/v2/terms/static/20180314_Copernicus_License_V1.1.pdf CMSAF SARAH-2 Pfeifroth, Uwe; Kothe, Steffen; Müller, Richard; Trentmann, Jörg; Hollmann, Rainer; Fuchs, Petra; Werscheck, Martin (2017): Surface Radiation Data Set - Heliosat (SARAH) - Edition 2, Satellite Application Facility on Climate Monitoring, DOI:10.5676/EUM_SAF_CM/SARAH/V002, https://doi.org/10.5676/EUM_SAF_CM/SARAH/V002 Terms of Use: https://www.eumetsat.int/cs/idcplg?IdcService=GET_FILE&dDocName=pdf_leg_data_policy&allowInterrupt=1&noSaveAs=1&RevisionSelectionMethod=LatestReleased Y1 - 2023 U6 - https://doi.org/10.5281/zenodo.8135586 ER - TY - GEN A1 - Birett, Falk A1 - Schumm, Leon A1 - Hofrichter, Andreas A1 - Heusgen, Valentin A1 - Rahim, Stefan T1 - Wasserstoffatlas Deutschland (Hydrogen Map) [Data set] N2 - Input files required for Hydrogen Map workflow in the project "Wasserstoffatlas Deutschland", funded by the BMBF. Y1 - 2025 U6 - https://doi.org/10.5281/zenodo.13960465 N1 - Further versions linked on Zenodo. ER - TY - CHAP A1 - Hinterreiter, Marion A1 - Brückl, Oliver A1 - Rauch, Johannes ED - Schulz, Detlef T1 - Methodology for long-term reactive power forecasts of medium-voltage grids T2 - NEIS 2025 : Conference on Sustainable Energy Supply and Energy Storage Systems, Hamburg, September 15 – 16, 2025 N2 - Understanding and assessing the long-term behavior of reactive power is crucial for power system planning and invest-ment decisions. This is particularly growing relevant for the lower voltage-grid levels, which are gaining importance due to significant changes in grid behavior, operational strategies, energy generation and consumption patterns. Currently, standardized methodologies for forecasting reactive power in medium-voltage grids are lacking, creating a gap in research and practical applications. To optimize grid investments and expansions, informed decisions based on reliable research and accurate forecasts are essential. This paper presents a methodology for long-term reactive power forecasting in me-dium-voltage grids, introducing a new approach to account for low- and medium-voltage grid interactions while address-ing common challenges like limited available grid data and scenario framework definition. The aim of the forecast is the future reactive power behaviour of a medium-voltage-grid at the high-voltage side of the high-voltage to medium-voltage transformer. The medium-voltage-level is modelled using a grid model approach, while low-voltage grids are being mod-elled using generic distribution grids. A 209-bus medium-voltage-grid model is used as an application example and to provide two exemplary use cases for a reactive power forecast for 2045. KW - reactive power KW - forecasting KW - long-term KW - medium-voltage level KW - grid level interaction Y1 - 2025 SN - 978-3-8007-6633-8 SP - 218 EP - 223 PB - VDE Verlag ER - TY - CHAP A1 - Stadler, Andreas A1 - Kraus, Hermann A1 - Brückl, Oliver ED - Technische Universität München, T1 - Proposing an Optimization Model for a techno-economic Evaluation of Energy Storage Systems T2 - PESS 2025 – IEEE Power and Energy Student Summit, October 08 – 10, 2025 in Munich, Germany N2 - During the global energy crisis in 2022, electricity prices increased drastically. This lead, together with an overall higher price volatility to possibly higher electrical energy storage system (ESS) profitability. To test if the investment in an ESS can now be more profitable, an approach for a techno-economic evaluation of ESS is presented in this paper, using an optimization algorithm to determine the optimal way of covering a load flow profile with electricity trading products on the electricity market with and without the use of an energy storage system. The cost differences between using or not using the storage system are assumed to be the profits of the ESS, which must exceed the (interest-bearing) investment costs over its lifetime. The correct way of operation of the optimization model is validated and several storage sizes and capacities as well as several years of the electricity market data was analyzed, once with a perfect forecast of all prices of the electricity trading products and once with a forecast based on the previous years purchasing strategy. The results show that, using the prognosis and a 2 % p.a. interest rate, only the storage combinations for 2.5 MWh/ 2.5 MW and 1 MWh/ 1 MW show profitability in 2023, whereas 2017 and 2020 show no profitability. KW - energy storage systems KW - techno economic evaluation KW - electricity trading KW - optimization KW - ess profitability Y1 - 2025 SN - 978-3-8007-6656-7 SP - 97 EP - 102 PB - VDE ER - TY - CHAP A1 - Hinterreiter, Marion A1 - Brückl, Oliver A1 - Rauch, Johannes ED - Technische Universität München, T1 - Challenges and Approaches for Long-Term Reactive Power Forecasting in Power Systems T2 - PESS 2025 – IEEE Power and Energy Student Summit, October 08 – 10, 2025 in Munich, Germany N2 - The transition from fossil fuels to renewable energy sources is driving profound changes across all voltage levels of the electrical grid, altering active power (P) as well as reactive power (Q) behavior. This transformation involves a shift from predominantly top-down, unidirectional electricity flows to bidirectional and increasingly complex flow patterns, fundamentally altering the operation and utilization of power systems. Many countries are already reporting notable changes in their transmission grid Q. This can lead to increased costs for grid expansion and compensation equipment, as well as grid losses. To minimize these losses and ensure grid stability and efficiency, understanding and forecasting Q long-term becomes essential. This paper addresses the challenges of long-term (1-20 years) Q forecasting in general by analyzing Q behavior in grids, the main influencing grid parameters, and reviewing existing forecasting approaches. It evaluates the applicability of these approaches and highlights current research gaps and trends. By focusing on this underexplored area, the paper aims to support the development of more advanced and reliable long-term Q forecasting techniques. KW - reactive power KW - forecasting KW - long-term KW - network models Y1 - 2025 SN - 978-3-8007-6656-7 SP - 109 EP - 114 PB - VDE Verlag ER - TY - CHAP A1 - Rauch, Johannes A1 - Brückl, Oliver A1 - Engel, Bernd ED - Schulz, Detlef, T1 - Optimal Reactive Power Planning by covering deficient voltage demands with additional reactive power sources using a sensitivity approach T2 - NEIS 2023 : Conference on Sustainable Energy Supply and Energy Storage Systems, Hamburg, September 4 – 5, 2023 N2 - The determination of the optimal location, types and size of additional required reactive power sources is a main interest of Reactive Power Planning (RPP) investigations and of this paper. The planning problem addresses the maintenance of voltage stability, which is an ancillary service in Germany, and can be formulated as a mixed-integer optimization prob-lem. The aim of this work is a techno-economically efficient coverage of the deficient steady state voltage deviation demands (VDD) by placing new reactive power sources with adequate size or extending the reactive power potential of existing sources. An optimization model is set up to solve the planning problem by using load flow voltage sensitivities, which quantify and evaluate the technical efficiency of new reactive power sources in relation to the present voltage deviation demands. Operating and investment costs are used as economic decision parameters. Within an application example, which is carried out with an exemplary transmission system, the solution of the planning problem is discussed. KW - reactive power planning KW - voltage control KW - optimal power flow KW - sensitivity analysis KW - system planning Y1 - 2023 UR - https://ieeexplore.ieee.org/document/10556672 SN - 978-3-8007-6134-0 SP - 223 EP - 230 PB - VDE Verlag CY - Berlin ER - TY - THES A1 - Thema, Martin Jiří T1 - Process optimization for microbial biosynthesis of methane in a trickle-bed reactor for Power-to-Gas applications: the ORBIT-process N2 - This thesis identifes Power-to-Gas in general and biological CO2-methanation in trickle-bed reactors in particular as promising energy storage and sector coupling technology ready for application but with further optimization potential. It reviews the global status and development of Power-to-Gas technology as to be of exponentially growing importance in energy systems changing towards renewable power supply and analyzes optimization and standardization potential for biological CO2-methanation in tricklebed reactors deriving an improved methanation process. Process development and experiments on hydrodynamical and biological improvement of such a setup were performed, leading to an optimized combination of a packing and microorganisms in pure culture embedded in the new ORBIT-process. First experimental results give evidence of successful application of different optimization approaches implemented in a technical center scale setup. N2 - Die vorliegende Arbeit analysiert Status und Entwicklung der Power-to-Gas-Technologien Wasserelektrolyse und CO2-Methanisierung hinsichtlich Kosten, technischer Parameter und energiepolitischer Stellung in den wichtigsten Einsatzländern. So konnte ein exponentieller Trend in zugebauter Anlagenleistung sowie deutliche Investitionskostendegressionen für alle untersuchten Technologien abgeleitet werden. Die Arbeit entwickelt Optimierungs- und Standardisierungsansätze für die biologische CO2-Methanisierung im Rieselbett-Reaktor, welche als eine der vielversprechenden Power-to-Gas-Anwendungen identifiziert wird. Mit Versuchen zur Verbesserung der hydrodynamischen Bedingungen im Reaktor sowie zu einer optimierten Verbindung aus Packungselementen und Mikroorganismen in Reinkultur wird daraus der neue ORBIT-Prozess abgeleitet. Erste Versuchsergebnisse aus einer realisierten Anlage im Technikumsmaßstab deuten hin auf die erfolgreiche Umsetzung der identifzierten Optimierungsansätze. T2 - Prozessoptimierung zur biologischen CO2-Methanisierung im Rieselbettreaktor f¨ur Power-to Gas-Anwendungen: der ORBIT-Prozess KW - CO2-methanation KW - ORBIT-process KW - Power-to-Gas KW - biological methanation KW - biomethanation KW - trickle-bed reactor Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?https://nbn-resolving.org/urn:nbn:de:bvb:29-opus4-150567 SN - 978-3-8440-7656-1 ER - TY - THES A1 - Mühlbauer, Christian T1 - Entwicklung einer Methodik zur Bewertung und Optimierung des vibroakustischen Verhaltens von Kraftstoffeinspritzsystemen N2 - Die vorliegende Dissertation befasst sich mit der akustischen Analyse von Kraftstoffein-spritzsystemen und deren NVH-Optimierung mithilfe ansteuerungstechnischer Maßnahmen. Da sich der Körper- und Luftschall beim Betrieb des Verbrennungsmotors mit anderen, nicht untersuchungsrelevanten Geräuschkomponenten überlagert, ist im Vollmotorbetrieb eine diffe-renzierte komponentenbasierte Geräuschmessung nicht möglich. Deshalb wurde ein NVH-Sys-temprüfstand entwickelt, der eine isolierte akustische Vermessung von Einspritzsystemen im seriennahen Systemverbund ermöglicht. Die Betriebsparameter des Einspritzsystems wurden an einem Vollmotor in einem leerlaufna-hen Motorbetriebspunkt erfasst und mithilfe eines speziellen Entwicklungssteuergeräts auf den NVH-Systemprüfstand transferiert. Ausgehend von dem definierten Referenzbetriebspunkt wurden sowohl die Randbedingungen als auch die Ansteuerstrategie variiert und deren Einfluss auf das akustische Verhalten analysiert. Dabei zeigten primär der Raildruck und die Anzahl der Einspritzungen einen ausgeprägten Einfluss auf die betrachteten (psycho-)akustischen Parame-ter Schalldruckpegel, Lautheit, Schärfe und Impulshaltigkeit. Zur akustischen Optimierung der mechatronischen Komponenten wurden zum einen der An-steuerstrom reduziert und zum anderen ein Bremsimpuls am Ende der Ansteuerung implemen-tiert. Dadurch konnten die mechanischen Prellereignisse deutlich reduziert werden. Mithilfe eines Einspritzratenmessgeräts wurde allerdings nachgewiesen, dass sich die Optimierungs-maßnahmen insbesondere auf die Streuung der eingespritzten Kraftstoffmasse negativ auswir-ken und damit ein Zielkonflikt aus Geräuschqualität und Primärfunktionen entsteht. Als signi-fikanter Kipppunkt wurde bei den Injektoren der Übergang vom linearen Vollhub-Betrieb zum ballistischen Teilhub-Betrieb identifiziert. Aus diesem Grund wurde die elektrische Ansteue-rung unter der Voraussetzung des Injektor-Vollhub-Betriebs optimiert. Bei der Beurteilung des Einflusses der NVH-optimierten Ansteuerprofile auf die Robustheit der mechatronischen Komponenten wirkten sich eine niedrige Versorgungsspannung sowie eine kurze Ansteuerdauer der Injektoren besonders negativ auf die Streuung der eingespritzten Kraftstoffmasse aus. Vor allem in Verbindung mit der stromreduzierten Ansteuerung wurden die Injektoren nicht mehr zuverlässig und reproduzierbar im Voll-Hub geöffnet. Weiterhin wur-den durch die Bremspuls-Applikation injektorspezifische Abweichungen im Schließverhalten weiter verstärkt und erhöhten damit auch die Abweichungen der mittleren eingespritzten Kraft-stoffmasse zwischen den untersuchten Injektor-Exemplaren. Abschließend wurde die Übertragbarkeit des Systemverhaltens ermittelt, indem die Optimie-rungsmaßnahmen auf einen weiteren Versuchsträger ausgeweitet wurden. Dabei zeigte sich, dass die Maßnahmen zwar grundsätzlich übertragbar waren, aber die Parametrierung bezüglich Ansteuerstromreduzierung und Bremspuls-Applikation zum Teil stark angepasst werden mussten. N2 - The present dissertation deals with the acoustic analysis of fuel injection systems and their NVH optimization by means of control measures. Since the structure-borne and airborne sound dur-ing operation of the combustion engine is superimposed with other noise components that are not relevant for the analysis, a differentiated component-based noise measurement is not possi-ble in full engine operation. For this reason, an NVH system test bench has been developed that enables isolated acoustic measurements of fuel injection systems in a near-series system com-pound. The operating parameters of the injection system were recorded on a full engine at an engine operating point close to idle and transferred to the NVH system test bench by means of a special development control unit. Beginning from the defined reference operating point, both the boundary conditions and the control strategy were varied and their influence on the acoustic behavior analyzed. Primarily, the rail pressure and the number of injections had a distinct in-fluence on the (psycho-)acoustic parameters considered: sound pressure level, loudness, sharp-ness and impulsiveness. To optimize the mechatronic components acoustically, the control current was reduced and a braking pulse was implemented at the end of the control. This significantly reduced the me-chanical bounce events. However, using an injection rate measurement device revealed that the optimization measures had a particularly negative effect on the scattering of the injected fuel mass, resulting in a trade-off between noise quality and performance. To this, the shift from linear full-stroke operation to ballistic partial-stroke operation of the injectors was identified as a significant tipping point. Therefore, the electrical control was optimized under the condition of injector full stroke operation. Considering the influence of the NVH optimized control profiles on the robustness of the mech-atronic components, particularly a low supply voltage and a short control duration of the injec-tors showed a negative effect on the scattering of the injected fuel mass. Especially in combi-nation with the reduced control current, the injectors were no longer able to open reliably and reproducibly in the full stroke. Additionally, the brake pulse application further increased in-jector-specific deviations in the closing behavior and thus increased the deviations of the mean injected fuel mass between the injector samples investigated. Finally, the transferability of the system behavior was determined by extending the optimization measures to another demonstrator. It turned out that the measures were generally transferable, but the parameterization with regard to control current reduction and brake pulse application had to be adapted considerably in some cases. KW - Brennstoffe KW - Explosivstoffe KW - Kraftstoffe KW - Technik der Verkehrsmittel Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:ma9:1-1981185920-1115312 ER - TY - THES A1 - Schwanzer, Peter T1 - Experimentelle Untersuchungen zur On-Board Überwachung von Partikelfiltern für den Einsatz an direkteinspritzenden Benzinmotoren N2 - This thesis deals with the development of a methodology for an improved on-board diagnosis of particulate filters in vehicles with gasoline direct injection (GDI) technology with regard to future emission legislations. In order to comply with statutory particle number limits, particulate filters are used in the exhaust gas aftertreatment for GDI-engines. The currently applied method for diagnostic purposes, a differential pressure sensor, will not be suitable for future legislations. Therefore, an on-board strategy with real-time ability shall be developed. To achieve this, the application of novel sensor concepts has been investigated, namely electrostatic soot sensors (ePM sensor) and radio frequency antennas (RF sensor). Due to the results of the ePM-sensors, no methodology for an on-board diagnosis based on an ePM sensor concept was made. The RF sensor showed varying sensitivities for different soot and different quantities of volatile components in the filter element. The analysis of the oxidation processes showed that the regeneration of the filter element is detected by the RF sensor. Furthermore, the stored amount of ash could be captured. Due to these findings, a concept for an improved on-board diagnosis strategy by means of an RF sensor concept was developed. In the course of the work it turned out that a combined sensor concept consisting of a differential pressure sensor and a RF sensor is most suitable. In a validation process, this sensor concept showed sufficient results concerning the detection capability of soot and ash loads as well as of the degree of damage of particulate filters. Especially for small amounts of ash, this sensor concept showed specific advantage. Also, the determination of the current amount of soot in the filter element proved to be suitable. Regarding the detection of damages, the sensor concept convinces through a higher sensitivity. KW - GDI KW - GPF KW - On-Board-Monitoring Y1 - 2022 SN - 978-3-8439-5101-2 PB - Verlag Dr. Hut CY - München ER - TY - THES A1 - Grauvogl, Dominik ED - Gerling, Dieter T1 - Multiphysikalische Auslegung einer fremderregten Synchronmaschine mit magnetischer Asymmetrie für einen Hochvolt-Achsantrieb N2 - In der vorliegenden Arbeit wird eine fremderregte Synchronmaschine als Achsantrieb für ein Elektrofahrzeug entwickelt. Als Grundlage hierfür dient ein bereits vorhandener Stator einer permanenterregten Synchronmaschine. Durch die Wiederverwendung des Stators ist eine maschinentypunabhängige Baukastenerweiterung in Form eines magnetfreien Rotors gegeben, wodurch die ökonomischen und ökologischen Nachteile der Permanentmagnete ausgeschlossen sind. Bei der Auslegung des Rotors wird von Beginn an ein multiphysikalischer Entwicklungsansatz gewählt, mit dem der praxistaugliche Einsatz für den modularen Baukasten sichergestellt ist. Dabei ist die elektromagnetische Auslegung iterativ auf die mechanische Blechpaketfestigkeit, das thermische Verhalten und die magnetischen Geräusche abgestimmt. In Kombination mit den gesetzten Restriktionen ergibt sich ein neuartiges asymmetrisches Polschuhdesign mit dem es möglich ist, das geforderte Drehmoment mit genügend kleiner Welligkeit ohne eine Rotorschrägung zu erreichen. Die Simulationsergebnisse sind durch die Vermessung eines aufgebauten Prototyps validiert und bestätigt. Ein abschließender Simulationsvergleich mit der baugleichen permanenterregten Synchronmaschine zeigt, dass die fremderregte Synchronmaschine hinsichtlich Performance, Wirkungsgrad und Geräuschverhalten eine konkurrenzfähige Alternative dazu ist. KW - Magnetische Asymmetrie KW - Traktionsmotor KW - Elektroantrieb KW - E-Mobilität KW - magnetfreier Antrieb KW - magnetische Geräusche KW - NVH KW - elektromagnetische Auslegung KW - Magnetkreisberechnung KW - Rotorkühlung KW - Luftkühlung KW - Erregerstromoptimierung KW - FEM KW - mechanische Festigkeit Y1 - 2022 UR - https://www.shaker.de/de/content/catalogue/index.asp?lang=de&ID=8&ISBN=978-3-8440-8553-2 SN - 9783844085532 PB - Shaker Verlag CY - Düren ER - TY - THES A1 - Weber, Sebastian T1 - Charakterisierung verschiedener Wassereinspritztechnologien für Ottomotoren N2 - Die Reduktion von Kraftstoffverbrauch und Schadstoffemission bei gleichzeitiger Verbesserung der Fahrleistung bei kleinerem Hubraum und reduzierter Zylinderzahl, die erhöhte Performance und die Kompatibilität mit elektrifizierten Komponenten beschreiben die aktuellen Ziele und Herausforderungen der modernen Ottomotorentwicklung. Um alle Herausforderungen zu erfüllen, muss ein stöchiometrischer Betrieb sichergestellt werden. Dabei kann es jedoch an der Volllast zur Überschreitung thermischer Grenzen im Abgaspfad kommen, weswegen die Abgastemperatur ohne Leistungsverluste abgesenkt werden muss. Die Wassereinspritzung kombiniert Downsizing, Leistungssteigerung und die Verbesserung der Schadstoffemissionen wirkungsvoll miteinander und könnte einen Beitrag zur Erreichung der Klimaziele leisten. Um ein optimales Systemlayout zu erarbeiten, sind prozessuale Betrachtungen oft nicht ausreichend. Vielmehr müssen die Phänomene im Brennraum beobachtet werden. Schwerpunktmäßig sind dies die Einbringung des Wassers, der Wandkontakt, die Spray- und Wandfilmverdampfung und somit die Wirksamkeit der Abgastemperaturreduktion und die Verbesserung des indizierten Wirkungsgrads. In einem ersten Schritt werden die Thermodynamik bei Wassereinspritzung analysiert und verschiedene Einspritztechnologien miteinander verglichen. Fokussiert wird die Verbrennung, die Veränderung in den gasförmigen und festen Abgasbestandteilen und die mechanische Belastung der Aggregate durch die Verbesserung der Zündwinkel. Die Mischungseinspritzung über den zentralen Hochdruckinjektor vereint den geringsten Wasserverbrauch mit bestmöglicher Schwerpunktlage, starker Reduktion des Partikelausstoßes und akzeptabler Erhöhung der mechanischen Belastung und ist damit das favorisierte Konzept. Neben den prozessualen Betrachtungen werden mit einem optisch zugänglichen Versuchsträger zwei laseroptische Messtechniken zur Visualisierung flüssigen Wassers und der spektralen Trennung zwischen Wasser und Kraftstoff entwickelt und validiert. Damit werden die verschiedenen Varianten optisch vermessen und die Sensitivität gegenüber veränderten Betriebs- und Randbedingungen ermittelt. Die Sammlereinspritzung zeigt die größten Tropfen, gefolgt von der Saugrohr- und der Mischungseinspritzung. Auch hat diese den mit Abstand größten Wandkontakt und die geringste Verdampfungsrate, ist zusätzlich anfällig für zyklische Schwankungen. Die Saugrohreinspritzung kennzeichnen kleine Tropfen, ein konzentriertes Einströmen durch den Ventilspalt, ein flächiger Wandfilm auf der Kolbenoberseite und die Verbesserung der Tropfenverdampfung durch Turbulenz und die Nutzung von Phasing. Favorit ist abermals die Mischungseinspritzung. Eine hohe Wandfilm- und unmittelbare Sprayverdampfung kennzeichnen das System, wobei eine Erhöhung des Einspritzdrucks die Verdampfungsrate signifikant verbessert. Außerdem ist die Einspritzdauer am geringsten und die Reproduzierbarkeit am größten, jedoch auch der applikative Aufwand. Am favorisierten System werden weitere Analysen durchgeführt, unter anderem zur Veränderung der Bauteiltemperaturen, der Vergleich mit einer Ethanoleinspritzung oder die vielversprechende Kombination in Form einer Wasser-Ethanol-Mischungseinspritzung. Auf Basis der experimentellen Erkenntnisse wird ein CFD-Verfahren vorgestellt, das die Wassereinspritzung abbildet und somit die Virtualisierung in der Produktentwicklung vorantreibt. Neben der methodischen Vorgehensweise wird das Verfahren validiert und am Einzylinder- und Vollmotorbetriebspunkt vorgestellt. Die auftretenden Unterschiede werden analysiert und ausgewählte Parameteranalysen durchgeführt. Mit den Simulationen kann nachvollzogen werden, wie das Wasser die Zylinderlaufbahn benetzt und mit dem Kolben interagiert. Zusammenfassend charakterisiert diese Arbeit die gängigen Wassereinspritzvarianten auf unterschiedlichen Ebenen, gibt Optimierungsempfehlungen für die bestmögliche Medienverdampfung und empfiehlt die Mischungseinspritzung als Systemlayout. N2 - The reduction in fuel consumption and pollutant emissions with simultaneous improving driving performance with a smaller displacement and a reduced number of cylinders, increased performance and compatibility with electrified components describe the current goals and challenges of modern gasoline engine development. In order to fulfil all challenges, stoichiometric operation must be ensured. At full load, however, thermal limits in the exhaust gas path can be exceeded, that is why the exhaust gas temperature must be reduced without loss of performance. The water injection effectively combines downsizing, increased performance and the improvement of pollutant emissions and could contribute to the achievement of the climate targets. In order to develop an optimal system layout, procedural considerations are often not sufficient. Rather, the phenomena in the combustion chamber must be observed. The focus is on the introduction of water, wall contact, spray, and wall film evaporation and thus the effectiveness of the exhaust gas temperature reduction and the improvement of the indicated efficiency. In a first step, the thermodynamics of water injection are analyzed, and different injection technologies compared. The focus is on the combustion, the change in the gaseous and solid exhaust gas components and the mechanical load on the engines by improving the ignition angle. The mixture injection via the central high-pressure injector combines the lowest water consumption with the best possible center of gravity, a strong reduction in particle emissions and an acceptable increase in the mechanical load and is therefore the preferred concept. In addition to the procedural considerations, two laser-optical measurement methods for visualizing liquid water and the spectral separation between water and fuel are being developed and validated using an optically accessible test engine. In this way, the different variants are optically measured and the sensitivity of changed operating and boundary conditions is determined. The manifold injection shows the largest droplets, followed by the manifold and the mixture injection. This has the greatest wall contact and the lowest evaporation rate by far but is susceptible to cyclical fluctuations. The intake manifold injection is characterized by small droplets, a concentrated inflow through the valve gap, a flat wall film on the top of the piston and the improvement of droplet evaporation through turbulence plus the use of phasing. Mixture injection is once again the favorite. The system is characterized by high wall film and direct spray evaporation, with an increase in the injection pressure significantly improving the evaporation rate. In addition, the injection duration is the shortest and the reproducibility greatest, but also the application effort. Further analyzes are carried out on the favored system, including changes in component temperatures, a comparison with an ethanol injection or the promising combination in the form of a water-ethanol mixture injection. Based on the experimental findings, a CFD process is presented that maps the water injection and thus drives the virtualization in product development. In addition to the methodical approach, the process is validated and presented at the single-cylinder and production engine operating point. The differences that arise are analyzed and the influence of selected parameters are pointed out. The simulations can be used to understand how the water wets the cylinder liner and interacts with the piston. In summary, this work characterizes the common water injection variants on different levels, gives optimization recommendations for the best possible media evaporation and recommends mixed injection as a system layout. KW - Kolbenkraftmaschine KW - Kraftstoffverbrauch KW - Schadstoffemission KW - Ottomotor KW - Einspritzanlage Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:ma9:1-1981185920-884176 ER - TY - THES A1 - Steininger, Peter T1 - Experimentelle und numerische Untersuchungen an einem solarselektiven Wärmedämmsystem N2 - Zur Erreichung der von der Bundesregierung gesteckten Ziele, bis zum Jahr 2050 den Primärenergiebedarf im Gebäudesektor und die Treibhausgasemissionen beträchtlich zu reduzieren, kommt der nachhaltigen und zukunftsorientierten energetischen Sanierung von Fassaden an Bestandsgebäuden besondere Bedeutung zu. Für die Applikation an Außenwänden steht eine Vielzahl an herkömmlichen und neuartigen Dämmsystemen zur Verfügung, die entweder eine signifikante Erhöhung des thermischen Widerstands der Gebäudehülle oder die Nutzung der Sonne als zusätzliche Energiequelle ermöglichen. Um die vorteilhaften Eigenschaften der Erzielung winterlicher solarer Gewinne, des sommerlichen Überhitzungsschutzes und der hohen Dämmwirkung an sonnenlosen Tagen in einem Dämmsystem zu vereinen, unter Berücksichtigung ökologischer Aspekte, sind Entwicklungen im Bereich von innovativen Fassadensystemen notwendig. Das Ziel dieser Arbeit war die konstruktive Entwicklung sowie die experimentelle und numerische Untersuchung eines rein mineralischen solarselektiven Wärmedämmsystems, das die oben genannten Zielsetzungen erfüllt. Zur Bewertung der Leistungsfähigkeit des entwickelten Systems wurden an einem Prototyp, in einem eigens konzipierten Differenzklimakammerprüfstand, stationäre und dynamische Untersuchungen zum winkelabhängigen Solarstrahlungs- und Wärmetransport durchgeführt und bauphysikalische Kenngrößen, die einen Vergleich mit gängigen Dämmsystemen erlauben, abgeleitet. Der experimentell ermittelte winkelabhängige Gesamtenergiedurchlassgrad, der als stationäre Kenngröße zur Bewertung der Solarstrahlungsleitung herangezogen wird, zeigt ein Maximum im Auslegungspunkt für Wintermonate (19° Einstrahlwinkel) und kann für hohe Sonnenstände, zur Vermeidung von sommerlichen Überhitzungseffekten, signifikant reduziert werden. Darüber hinaus wurden die experimentellen Ergebnisse zur Validierung von stationären und dynamischen multiphysikalischen Simulationsmodellen des solarselektiven Wärmedämmsystems eingesetzt, welche ein tieferes Verständnis des Wärme- und Strahlungstransports ermöglichen. Unter Verwendung der validierten Simulationsmodelle wurden, ausgehend vom Prototyp, die wesentlichen konstruktiven Einflussfaktoren auf die Solarleitung und die Dämmwirkung des Systems ermittelt und das Verbesserungspotential entsprechend quantifiziert. Zudem wurden in einer jährlichen simulativen Untersuchung, unter Verwendung realer Wetterdaten, mithilfe zweier verbesserter Varianten des solarselektiven Wärmedämmsystems, die Heizenergieeinsparpotentiale in der Winter- und Übergangszeit gegenüber einer herkömmlich gedämmten Wandkonstruktion nachgewiesen. N2 - In order to reach the objectives of the Federal Government to considerably reduce the primary energy demand in the building sector and greenhouse gas emissions by the year 2050, the sustainable and future-oriented energetic retrofitting of existing buildings’ facades is of particular importance. A variety of conventional and novel thermal insulation systems are available for the application on exterior walls, which allow either a significant increase of the thermal resistance of the building envelope or the use of the sun as an additional energy source. In order to combine the beneficial properties of obtaining winter solar gains, summer overheating protection and high thermal insulation on sunless days in one insulating system, while taking into account ecological aspects, developments in the field of innovative facade systems are necessary. The objective of this work was the development as well as the experimental and numerical investigation of a purely mineral solar selective thermal insulation system that meets the aforementioned objectives. In order to assess the performance of the developed system, steady state and dynamic investigations of the angle-dependent solar irradiation and heat transport were carried out using a prototype in a differential climatic chamber test bench, so that characteristic building physics parameters, which allow a comparison with conventional thermal insulation systems, can be derived. The experimentally determined angle-dependent total solar energy transmittance, which is used as a steady state parameter for the assessment of the solar radiation transmission through the system, shows a maximum at the design point in winter months (19° incidence angle) and can be significantly reduced for high sun angles, thus avoiding overheating effects in summer. Furthermore, the experimental results were used for the validation of steady state and dynamic multiphysical simulation models of the solar selective thermal insulation system, which allow a deeper understanding of the heat and radiation transport. Using the validated simulation models, based on the prototype, the main constructive factors influencing the solar transmission and the thermal insulation performance of the system were determined and the potential for improvements was quantified accordingly. In addition, in a yearly simulation study using real weathering data, two improved variants of the solar selective thermal insulation system were used to show the heating energy savings in the winter and transition period compared to a conventionally insulated wall construction. Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:91-diss-20220614-1615021-1-1 UR - https://mediatum.ub.tum.de/?id=1615021 ER - TY - CHAP A1 - Sterner, Michael ED - Faulstich, Martin ED - Mocker, Mario T1 - WBGU Gutachten - zukunftsfähige Bioenergie und nachhaltige Landnutzung T2 - Biomasse & Abfall : Emissionen mindern und Rückstände nutzen (Verfahren & Werkstoffe für die Energietechnik ; 5) Y1 - 2009 SN - 9783981039146 SP - 23 EP - 28 PB - Dorner Printconcept CY - Sulzbach-Rosenberg ER -