@inproceedings{KohlbergerWildKasperetal.2021, author = {Kohlberger, David-Sharif and Wild, Dominik and Kasper, Stefan and Czupalla, Markus}, title = {Modeling and analyses of a thermal passively stabilized LEO/GEO star tracker with embedded phase change material applying the Infused Thermal Solutions (ITS) method}, series = {ICES202: Satellite, Payload, and Instrument Thermal Control}, booktitle = {ICES202: Satellite, Payload, and Instrument Thermal Control}, publisher = {Texas Tech University}, address = {Lubbock, Tex.}, pages = {12 Seiten}, year = {2021}, abstract = {Phase change materials offer a way of storing excess heat and releasing it when it is needed. They can be utilized as a method to control thermal behavior without the need for additional energy. This work focuses on exploring the potential of using phase change materials to passively control the thermal behavior of a star tracker by infusing it with a fitting phase change material. Based on the numerical model of the star trackers thermal behavior using ESATAN-TMS without implemented phase change material, a fitting phase change material for selected orbits is chosen and implemented in the thermal model. The altered thermal behavior of the numerical model after the implementation is analyzed for different amounts of the chosen phase change materials using an ESATAN-based subroutine developed by the FH Aachen. The PCM-modelling-subroutine is explained in the paper ICES-2021-110. The results show that an increasing amount of phase change material increasingly damps temperature oscillations. Using an integral part structure some of the mass increase can be compensated.}, language = {en} } @inproceedings{WildCzupallaFoerstner2021, author = {Wild, Dominik and Czupalla, Markus and F{\"o}rstner, Roger}, title = {Modeling, prediction and test of additive manufactured integral structures with embedded lattice and phase change material applying Infused Thermal Solutions (ITS)}, series = {ICES104: Advances in Thermal Control Technology}, booktitle = {ICES104: Advances in Thermal Control Technology}, publisher = {Texas Tech University}, address = {Lubbock, Tex.}, pages = {12 Seiten}, year = {2021}, abstract = {Infused Thermal Solutions (ITS) introduces a method for passive thermal control to stabilize structural components thermally without active heating and cooling systems, but with phase change material (PCM) for thermal energy storage (TES), in combination with lattice - both embedded in additive manufactured functional structures. In this ITS follow-on paper a thermal model approach and associated predictions are presented, related on the ITS functional breadboards developed at FH Aachen. Predictive TES by PCM is provided by a specially developed ITS PCM subroutine, which is applicable in ESATAN. The subroutine is based on the latent heat storage (LHS) method to numerically embed thermo-physical PCM behavior. Furthermore, a modeling approach is introduced to numerically consider the virtual PCM/lattice nodes within the macro-encapsulated PCM voids of the double wall ITS design. Related on these virtual nodes, in-plane and out-of-plane conductive links are defined. The recent additive manufactured ITS breadboard series are thermally cycled in the thermal vacuum chamber, both with and without embedded PCM. Related on breadboard hardware tests, measurement results are compared with predictions and are subsequently correlated. The results of specific simulations and measurements are presented. Recent predictive results of star tracker analyses are also presented in ICES-2021-106, based on this ITS PCM subroutine.}, language = {en} } @inproceedings{BungLangohrWaldenberger2023, author = {Bung, Daniel Bernhard and Langohr, Phillip and Waldenberger, Lisa}, title = {Influence of cycle number in CFD studies of labyrinth weirs}, series = {Proceedings of the 40th IAHR World Congress (Vienna, 2023)}, booktitle = {Proceedings of the 40th IAHR World Congress (Vienna, 2023)}, editor = {Habersack, Helmut and Tritthart, Michael}, publisher = {International Association for Hydro-Environment Engineering and Research (IAHR)}, address = {Madrid}, isbn = {978-90-833476-1-5}, issn = {L 2521-7119 (online)}, doi = {10.3850/978-90-833476-1-5_iahr40wc-p0531-cd}, year = {2023}, abstract = {The major advantage of labyrinth weirs over linear weirs is hydraulic efficiency. In hydraulic modeling efforts, this strength contrasts with limited pump capacity as well as limited computational power for CFD simulations. For the latter, reducing the number of investigated cycles can significantly reduce necessary computational time. In this study, a labyrinth weir with different cycle numbers was investigated. The simulations were conducted in FLOW-3D HYDRO as a Large Eddy Simulation. With a mean deviation of 1.75 \% between simulated discharge coefficients and literature design equations, a reasonable agreement was found. For downstream conditions, overall consistent results were observed as well. However, the orientation of labyrinth weirs with a single cycle should be chosen carefully under consideration of the individual research purpose.}, language = {en} } @inproceedings{MayntzKeimerDahmannetal.2022, author = {Mayntz, Joscha and Keimer, Jona and Dahmann, Peter and Hille, Sebastian and Stumpf, Eike and Fisher, Alex and Dorrington, Graham}, title = {Electrical Drive and Regeneration in General Aviation Flight with Propellers}, series = {Deutscher Luft- und Raumfahrtkongress 2020}, booktitle = {Deutscher Luft- und Raumfahrtkongress 2020}, publisher = {DGLR}, address = {Bonn}, doi = {10.25967/530100}, pages = {8 Seiten}, year = {2022}, abstract = {Electric flight has the potential for a more sustainable and energy-saving way of aviation compared to fossil fuel aviation. The electric motor can be used as a generator inflight to regenerate energy during descent. Three different approaches to regenerating with electric propeller powertrains are proposed in this paper. The powertrain is to be set up in a wind tunnel to determine the propeller efficiency in both working modes as well as the noise emissions. Furthermore, the planned flight tests are discussed. In preparation for these tests, a yaw stability analysis is performed with the result that the aeroplane is controllable during flight and in the most critical failure case. The paper shows the potential for inflight regeneration and addresses the research gaps in the dual role of electric powertrains for propulsion and regeneration of general aviation aircraft.}, language = {en} } @inproceedings{TreulingCzarneckiWolf2023, author = {Treuling, Clemens and Czarnecki, Christian and Wolf, Martin R.}, title = {Projekt WiLMo - Wirtschaftsinformatik Lehr- und Lernmodule}, series = {Angewandte Forschung in der Wirtschaftsinformatik 2023 : Tagungsband zur 36. AKWI-Jahrestagung}, booktitle = {Angewandte Forschung in der Wirtschaftsinformatik 2023 : Tagungsband zur 36. AKWI-Jahrestagung}, pages = {161 -- 169}, year = {2023}, abstract = {Die potenziellen Auswirkungen der Digitalisierung auf die Lehre sind seit langem Gegenstand ausf{\"u}hrlicher Diskussionen innerhalb der Wirtschaftsinformatik (WI) (z. B. in Auth et al. 2021, Barton et al. 2019, Klotz et al. 2019). Nicht zuletzt der in nahezu allen Wirtschaftszweigen bestehende Mangel an qualifizierten Fachkr{\"a}ften lenkt den Diskurs auf einen verbesserten Zugang zu Bildung und gleichen Bildungschancen. Aus dieser Vision heraus und dem Schub der Digitalisierung entstehen Bildungskonzepte wie Open Educational Resources (OER), die gesellschaftlichen Problemen, wie dem des Fachkr{\"a}ftemangels, entgegenwirken sollen. Im Rahmen dieses Kurzbeitrags wird das Projekt WiLMo - "Wirtschaftsinformatik Lehr- und Lernmodule" vorgestellt. WiLMo wird im Rahmen von OERContent.nrw unter Beteiligung von sechs Hochschulen entwickelt und gef{\"o}rdert. Alle Projektbeteiligten arbeiten gemeinsam daran, einheitliche digitale Lehr- und Lernmaterialien im OER-Format f{\"u}r die Kernmodule der Wirtschaftsinformatik zu entwickeln und in garantiert hoher Qualit{\"a}t zur Verf{\"u}gung zu stellen.}, language = {de} } @inproceedings{VladovaUllrichSultanowetal.2023, author = {Vladova, Gergana and Ullrich, Andr{\´e} and Sultanow, Eldar and Tobolla, Marinho and Sebrak, Sebastian and Czarnecki, Christian and Brockmann, Carsten}, title = {Visual analytics for knowledge management}, series = {INFORMATIK 2023 - Designing Futures: Zuk{\"u}nfte gestalten}, booktitle = {INFORMATIK 2023 - Designing Futures: Zuk{\"u}nfte gestalten}, publisher = {GI - Gesellschaft f{\"u}r Informatik}, address = {Bonn}, isbn = {978-3-88579-731-9}, issn = {1617-5468}, doi = {10.18420/inf2023_187}, pages = {1851 -- 1870}, year = {2023}, abstract = {The management of knowledge in organizations considers both established long-term processes and cooperation in agile project teams. Since knowledge can be both tacit and explicit, its transfer from the individual to the organizational knowledge base poses a challenge in organizations. This challenge increases when the fluctuation of knowledge carriers is exceptionally high. Especially in large projects in which external consultants are involved, there is a risk that critical, company-relevant knowledge generated in the project will leave the company with the external knowledge carrier and thus be lost. In this paper, we show the advantages of an early warning system for knowledge management to avoid this loss. In particular, the potential of visual analytics in the context of knowledge management systems is presented and discussed. We present a project for the development of a business-critical software system and discuss the first implementations and results.}, language = {en} } @inproceedings{LosseGehrkeUllrichetal.2022, author = {Losse, Ann-Kathrin and Gehrke, Melanie and Ullrich, Andr{\´e} and Czarnecki, Christian and Sultanow, Eldar and Breithaupt, Carsten and Koch, Christian}, title = {Entwicklung einer Open-Data-Referenzarchitektur f{\"u}r die Luftfahrtindustrie}, series = {INFORMATIK 2022 - Informatik in den Naturwissenschaften, Proceedings}, booktitle = {INFORMATIK 2022 - Informatik in den Naturwissenschaften, Proceedings}, publisher = {GI - Gesellschaft f{\"u}r Informatik}, address = {Bonn}, isbn = {978-3-88579-720-3}, issn = {1617-5468}, doi = {10.18420/inf2022_103}, pages = {1203 -- 1209}, year = {2022}, abstract = {Open Data impliziert die freie Zug{\"a}nglichkeit, Verf{\"u}gbarkeit und Wiederverwendbarkeit von Datens{\"a}tzen. Obwohl hochwertige Datens{\"a}tze {\"o}ffentlich verf{\"u}gbar sind, ist der Zugang zu diesen und die Transparenz {\"u}ber die Formate nicht immer gegeben. Dies mindert die optimale Nutzung des Potenzials zur Wertsch{\"o}pfung, trotz der vorherrschenden Einigkeit {\"u}ber ihre Chancen. Denn Open Data erm{\"o}glicht das Vorantreiben von Compliance-Themen wie Transparenz und Rechenschaftspflicht bis hin zur F{\"o}rderung von Innovationen. Die Nutzung von Open Data erfordert Mut und eine gemeinsame Anstrengung verschiedener Akteure und Branchen. Im Rahmen des vorliegenden Beitrags werden auf Grundlage des Design Science-Ansatzes eine Open Data Capability Map sowie darauf aufbauend eine Datenarchitektur f{\"u}r Open Data in der Luftfahrtindustrie an einem Beispiel entwickelt.}, language = {de} } @inproceedings{KahraBreussKleefeldetal.2024, author = {Kahra, Marvin and Breuß, Michael and Kleefeld, Andreas and Welk, Martin}, title = {An Approach to Colour Morphological Supremum Formation Using the LogSumExp Approximation}, series = {Discrete Geometry and Mathematical Morphology}, booktitle = {Discrete Geometry and Mathematical Morphology}, editor = {Brunetti, Sara and Frosini, Andrea and Rinaldi, Simone}, publisher = {Springer}, address = {Cham}, isbn = {978-3-031-57793-2}, doi = {10.1007/978-3-031-57793-2_25}, pages = {325 -- 337}, year = {2024}, abstract = {Mathematical morphology is a part of image processing that has proven to be fruitful for numerous applications. Two main operations in mathematical morphology are dilation and erosion. These are based on the construction of a supremum or infimum with respect to an order over the tonal range in a certain section of the image. The tonal ordering can easily be realised in grey-scale morphology, and some morphological methods have been proposed for colour morphology. However, all of these have certain limitations. In this paper we present a novel approach to colour morphology extending upon previous work in the field based on the Loewner order. We propose to consider an approximation of the supremum by means of a log-sum exponentiation introduced by Maslov. We apply this to the embedding of an RGB image in a field of symmetric 2x2 matrices. In this way we obtain nearly isotropic matrices representing colours and the structural advantage of transitivity. In numerical experiments we highlight some remarkable properties of the proposed approach.}, language = {en} } @inproceedings{BurgethKleefeldZhangetal.2022, author = {Burgeth, Bernhard and Kleefeld, Andreas and Zhang, Eugene and Zhang, Yue}, title = {Towards Topological Analysis of Non-symmetric Tensor Fields via Complexification}, series = {Discrete Geometry and Mathematical Morphology}, booktitle = {Discrete Geometry and Mathematical Morphology}, editor = {Baudrier, {\´E}tienne and Naegel, Beno{\^i}t and Kr{\"a}henb{\"u}hl, Adrien and Tajine, Mohamed}, publisher = {Springer}, address = {Cham}, isbn = {978-3-031-19897-7}, doi = {10.1007/978-3-031-19897-7_5}, pages = {48 -- 59}, year = {2022}, abstract = {Fields of asymmetric tensors play an important role in many applications such as medical imaging (diffusion tensor magnetic resonance imaging), physics, and civil engineering (for example Cauchy-Green-deformation tensor, strain tensor with local rotations, etc.). However, such asymmetric tensors are usually symmetrized and then further processed. Using this procedure results in a loss of information. A new method for the processing of asymmetric tensor fields is proposed restricting our attention to tensors of second-order given by a 2x2 array or matrix with real entries. This is achieved by a transformation resulting in Hermitian matrices that have an eigendecomposition similar to symmetric matrices. With this new idea numerical results for real-world data arising from a deformation of an object by external forces are given. It is shown that the asymmetric part indeed contains valuable information.}, language = {en} } @inproceedings{BeckerBragard2024, author = {Becker, Tim and Bragard, Michael}, title = {Low-Voltage DC Training Lab for Electric Drives - Optimizing the Balancing Act Between High Student Throughput and Individual Learning Speed}, series = {2024 IEEE Global Engineering Education Conference (EDUCON)}, booktitle = {2024 IEEE Global Engineering Education Conference (EDUCON)}, publisher = {IEEE}, address = {New York, NY}, issn = {2165-9559}, doi = {10.1109/EDUCON60312.2024.10578902}, pages = {8 Seiten}, year = {2024}, abstract = {After a brief introduction of conventional laboratory structures, this work focuses on an innovative and universal approach for a setup of a training laboratory for electric machines and drive systems. The novel approach employs a central 48 V DC bus, which forms the backbone of the structure. Several sets of DC machine, asynchronous machine and synchronous machine are connected to this bus. The advantages of the novel system structure are manifold, both from a didactic and a technical point of view: Student groups can work on their own performance level in a highly parallelized and at the same time individualized way. Additional training setups (similar or different) can easily be added. Only the total power dissipation has to be provided, i.e. the DC bus balances the power flow between the student groups. Comparative results of course evaluations of several cohorts of students are shown.}, language = {en} }