@article{KuepperArtmannPischingeretal., author = {K{\"u}pper, Carsten and Artmann, Christina and Pischinger, Stefan and Rabl, Hans-Peter}, title = {Schmier{\"o}lverd{\"u}nnung von direkteinspritzenden Ottomotoren unter Kaltstartrandbedingungen}, series = {MTZ - Motortechnische Zeitschrift}, volume = {74}, journal = {MTZ - Motortechnische Zeitschrift}, number = {9}, publisher = {Springer Vieweg}, address = {Wiesbaden}, doi = {10.1007/s35146-013-0208-1}, pages = {710 -- 715}, language = {de} } @inproceedings{ArrietaCastroChavesRilletal., author = {Arrieta Castro, Abel and Chaves, Rafael B. and Rill, Georg and Weber, Hans I.}, title = {Use of Integrated Control to Enhance the Safety of Vehicles in Run-Off-Road Scenarios}, series = {Proceedings of DINAME 2017 : Selected Papers of the XVII International Symposium on Dynamic Problems of Mechanics}, booktitle = {Proceedings of DINAME 2017 : Selected Papers of the XVII International Symposium on Dynamic Problems of Mechanics}, editor = {Fleury, Agenor de T. and Rade, Domingos A. and Kurka, R. G.}, edition = {1. Auflage}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-91217-2}, issn = {2195-4356}, doi = {10.1007/978-3-319-91217-2_30}, pages = {431 -- 443}, abstract = {In this work, an integrated vehicle control system (IC) is tested in run-off-road scenarios. The integrated approach was employed in order to coordinate vehicle control systems, i.e. the Anti-Lock Brake System (ABS), Four-wheel Steering (4WS) and the Electronic Stability Program (ESP). To perform a run-off-road maneuver, a fuzzy virtual test driver was designed. By receiving the lateral position of an obstacle and the vehicle's relative yaw angle, the virtual test driver is capable of following a reference trajectory. Furthermore, to test the performance of the standalone controllers, i.e. ABS, ESP and 4WS, individual maneuvers are performed using a multibody vehicle model. The vehicle without any coordination between the control systems is used as reference. For the simulation results, it is concluded that the IC improves the vehicle stability and maneuverability in comparison with the non-integrated approach.}, language = {en} } @inproceedings{EberhartChungHaumeretal., author = {Eberhart, Philip and Chung, Tek Shan and Haumer, Anton and Kral, Christian}, title = {Open Source Library for the Simulation of Wind Power Plants}, series = {Proceedings of the 11th International Modelica Conference, Versailles, France, September 21-23, 2015}, booktitle = {Proceedings of the 11th International Modelica Conference, Versailles, France, September 21-23, 2015}, address = {Link{\"o}ping}, doi = {10.3384/ecp15118929}, pages = {929 -- 936}, abstract = {This paper presents the new open source Modelica libraryWindPowerPlants. For the economic assessment of either a wind power plant or an entire wind park, the accurate prediction of the energy output is essential. Such prediction is usually performed by means of calculations based on statistical wind data. The proposed WindPowerPlants library is capable of assessing the energy output both for statistical and real wind data based on time domain simulations. In the presented version of the library wind turbine models are modeled with pitch control. The generator models have variable speed and an optional connector to the mains. The entire library is based on power balance conditions and losses are fully neglected. Yet, the library can be extended towards more detailed models considering different types of losses. The structure and components of the library are presented. Simulations examples are shown and compared with reference data. The applicability of the proposed WindPowerPlants library is demonstrated and possible enhancements are discussed.}, language = {en} } @inproceedings{MuchaMottokKraemer, author = {Mucha, Matthias and Mottok, J{\"u}rgen and Kr{\"a}mer, Stefan}, title = {Estimation of Worst Case Response Time Boundaries in Multi-Core Real-Time Systems}, series = {2017 International Conference on Applied Electronics (AE), 5-6 Sept. 2017, Pilsen}, booktitle = {2017 International Conference on Applied Electronics (AE), 5-6 Sept. 2017, Pilsen}, publisher = {IEEE}, isbn = {978-80-261-0641-8}, issn = {1803-7232}, doi = {10.23919/ae.2017.8053598}, pages = {1 -- 6}, abstract = {We address a novel probabilistic approach to estimate the Worst Case Response Time boundaries of tasks. Multi-core real-time systems process tasks in parallel on two or more cores. Tasks in our contribution may preempt other tasks, block tasks with semaphores to access global shared resources, or migrate to another core. The depicted task behavior is random. The shape of collected response times of a task within a processing time is multimodal. Extreme Value approaches need unimodal response time distributions to estimate the Worst Case Response Time of tasks. The new proposed method derives a set of three task set shapes from the source task set. It is used to minimize the uncertainty of random task behavior by maximizing the coverage of possible Worst Case Response Times. The case study evaluates the new proposed estimation method by the use of dynamically generated random tasks with varying task properties.}, language = {en} } @article{KuepperArtmannPischingeretal., author = {K{\"u}pper, Carsten and Artmann, Christina and Pischinger, Stefan and Rabl, Hans-Peter}, title = {Lube-Oil Dilution of Gasoline Direct-Injection Engines with Ethanol Fuels}, series = {MTZ worldwide}, volume = {74}, journal = {MTZ worldwide}, number = {9}, publisher = {Springer}, address = {Berlin}, doi = {10.1007/s38313-013-0090-8}, pages = {64 -- 69}, language = {en} } @book{FreniDawoudBonaccorsietal., author = {Freni, Angelo and Dawoud, Belal and Bonaccorsi, Lucio Maria and Chmielewski, Stefanie and Frazzica, Andrea and Calabrese, Luigi and Restuccia, Giovanni}, title = {Characterization of Zeolite-Based Coatings for Adsorption Heat Pumps}, publisher = {Springer}, address = {Berlin}, doi = {10.1007/978-3-319-09327-7}, pages = {96 S.}, abstract = {This book proposes a radically new approach for characterizing thermophysical and mechanical properties of zeolite-based adsorbent coatings for Adsorptive Heat Transformers (AHT). It presents a developed standard protocol for the complete characterization of advanced coated adsorbers. Providing an in-depth analysis of the different procedures necessary for evaluating the performance of adsorbers, it also presents an analysis of their stability under the hydrothermal and mechanical stresses during their entire life cycle. Adsorptive Heat Transformers (AHT), especially adsorption chillers and heat pumps, are considered to be promising technologies to increase thermal energy efficiency. Nevertheless, an overall increase in performance of this apparatus is necessary for them to be considered a mature technology to be used commercially. Development of innovative coated adsorbers can be perceived as a key issue for the enhancement of AHT technology. This procedure relies on the deposition, either by means of a binder or by direct crystallization, of the adsorbent material over a metallic heat exchanger, aiming at the improvement of the heat transfer between the external heat source and the adsorbent itself. This book offers a valuable resource to those working on the development of novel adsorbent materials and advanced adsorbent beds for heating and cooling applications. It is also intended for researchers interested in renewable energy and energy efficiency.}, language = {en} } @inproceedings{Rill, author = {Rill, Georg}, title = {TMeasy 6.0-A handling tire model that incorporates the first two belt eigenmodes}, series = {Proceedings of the XI International Conference on Structural Dynamics (EURODYN 2020): Athens, Greece, 23.11.2020 - 26.11.2020}, booktitle = {Proceedings of the XI International Conference on Structural Dynamics (EURODYN 2020): Athens, Greece, 23.11.2020 - 26.11.2020}, publisher = {EASD Procedia}, doi = {10.47964/1120.9054.18673}, pages = {676 -- 689}, abstract = {TMeasy 6.0, an extension to the standard TMeasy tire model of version 5.3, takes the relevant first two rigid body eigenmodes of the belt into consideration. These modes represent the in plane longitudinal and rotational movements of the belt relative to the rim. The dynamics of the longitudinal force is of higher order then and reproduces the tire wheel vibrations, required for indirect tire-pressure monitoring systems (iTPMS), sufficiently well. A tailored implicit solver, which takes the stiff coupling between the longitudinal force and the belt motions into account, still provides real-time performance in addition. Simulation examples show that a rigid body vehicle model equipped with TMeasy 6.0 makes it possible to investigate second generation indirect tire-pressure monitoring systems.}, 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{HaenninenNiemetzSchoepe, author = {H{\"a}nninen, Risto and Niemetz, Michael and Schoepe, Wilfried}, title = {Transition to turbulence in oscillatory superflows}, series = {ETC 2013 - 14th European Turbulence Conference 2020: 2 September 2013 - 4 September 2013, Lyon, France}, booktitle = {ETC 2013 - 14th European Turbulence Conference 2020: 2 September 2013 - 4 September 2013, Lyon, France}, abstract = {The flow of superfluid helium-4 at very low temperatures around an oscillating microsphere has been studied in detail. At small oscillation amplitudes the drag force is linear in velocity amplitude. Above a critical velocity amplitude vc a transition from potential flow to turbulent flow is signaled by a large and nonlinear drag force that scales as (v2 - v2 c ), where vc is found to be independent of temperature (below 1 K) and of driving force. Interestingly, the critical velocity is found to scale as vc ~ √κω, where κ = h/m ≈ 10-7 m2/s (h is Planck's constant and m is the mass of a helium-4 atom) is the circulation quantum of the superfluid vortices and ω/2π is the oscillation frequency ranging from about 120 Hz to 700 Hz. We also observe slightly above vc that the flow pattern is unstable and switches intermittently between potential flow and turbulence. From time series recorded at constant drive and temperature we have investigated the statistical properties of this switching phenomenon. In this talk the universal law vc ~ √κω will be discussed in detail. It can be derived theoretically in various ways: firstly, from a qualitative but very general argument based on the "superfluid Reynolds number" Rs = vl/κ where v is the flow velocity and l is a characteristic length scale, secondly, and in more detail, from Kopnin's equation of the time dependence of the vortex line density, and, finally, we have obtained this law rigorously by dynamical scaling of the equations of motion of vortex dynamics.}, 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} }