@inproceedings{TamaldinEschTonolietal.2020, author = {Tamaldin, Noreffendy and Esch, Thomas and Tonoli, Andrea and Reisinger, Karl Heinz and Sprenger, Hanna and Razuli, Hisham}, title = {ERASMUS+ United CBHE Automotive International Collaboration from European to South East Asia}, series = {Proceedings of the 2nd African International Conference on Industrial Engineering and Operations Management}, booktitle = {Proceedings of the 2nd African International Conference on Industrial Engineering and Operations Management}, publisher = {IEOM Society International}, address = {Southfield}, isbn = {978-1-7923-6123-4}, issn = {2169-8767}, pages = {2970 -- 2972}, year = {2020}, abstract = {The industrial revolution especially in the IR4.0 era have driven many states of the art technologies to be introduced. The automotive industry as well as many other key industries have also been greatly influenced. The rapid development of automotive industries in Europe have created wide industry gap between European Union (EU) and developing countries such as in South East Asia (SEA). Indulging this situation, FH JOANNEUM, Austria together with European partners from FH Aachen, Germany and Politecnico di Torino, Italy are taking initiative to close down the gap utilizing the Erasmus+ United Capacity Building in Higher Education grant from EU. A consortium was founded to engage with automotive technology transfer using the European framework to Malaysian, Indonesian and Thailand Higher Education Institutions (HEI) as well as automotive industries in respective countries. This could be achieved by establishing Engineering Knowledge Transfer Unit (EKTU) in respective SEA institutions guided by the industry partners in their respective countries. This EKTU could offer updated, innovative and high-quality training courses to increase graduate's employability in higher education institutions and strengthen relations between HEI and the wider economic and social environment by addressing University-industry cooperation which is the regional priority for Asia. It is expected that, the Capacity Building Initiative would improve the quality of higher education and enhancing its relevance for the labor market and society in the SEA partners. The outcome of this project would greatly benefit the partners in strong and complementary partnership targeting the automotive industry and enhanced larger scale international cooperation between the European and SEA partners. It would also prepare the SEA HEI in sustainable partnership with Automotive industry in the region as a mean of income generation in the future.}, language = {en} } @incollection{HeimesKampkerKehreretal.2023, author = {Heimes, Heiner Hans and Kampker, Achim and Kehrer, Mario and D{\"u}nnwald, Simon and Heetfeld, Lennart and Polzenberg, Jens and Budde, Lucas and Keusen, Maximilian and Pandey, Rahul and R{\"o}th, Thilo}, title = {Fahrzeugstruktur}, series = {Elektromobilit{\"a}t: Grundlagen einer Fortschrittstechnologie}, booktitle = {Elektromobilit{\"a}t: Grundlagen einer Fortschrittstechnologie}, editor = {Kampker, Achim and Heimes, Heiner Hans}, publisher = {Springer Vieweg}, address = {Berlin}, isbn = {978-3-662-65811-6 (Print)}, doi = {10.1007/978-3-662-65812-3_5}, pages = {69 -- 106}, year = {2023}, abstract = {Um sowohl Treibhausgas-Emissionen zu verringern als auch Kraftstoffressourcen zu schonen, wird zunehmend an einer Transformation konventionell angetriebener Kraftfahrzeuge hin zu elektrifizierten Antriebskonzepten gearbeitet. Basierend auf herk{\"o}mmlichen Fahrzeugen mit Verbrennungsmotor wurde eine Vielzahl neuer Antriebssysteme mit verschiedenem Elektrifizierungsgrad entwickelt. Mitte der 1990er-Jahre kamen erste Fahrzeuge mit einem Hybridantrieb auf den Markt. Die Kombination aus Verbrennungs- und Elektromotor erlaubt eine Verbrauchsreduktion und Bremsenergier{\"u}ckgewinnung sowie lokal emissionsfreies Fahren.}, language = {de} } @incollection{HeimesKampkerDornetal.2023, author = {Heimes, Heiner Hans and Kampker, Achim and Dorn, Benjamin and Kehrer, Mario and D{\"u}nnwald, Simon and Badura, Dennis and Terren, Maximilian and R{\"o}th, Thilo}, title = {Produktionsprozesse der Fahrzeugstruktur}, series = {Elektromobilit{\"a}t: Grundlagen einer Fortschrittstechnologie}, booktitle = {Elektromobilit{\"a}t: Grundlagen einer Fortschrittstechnologie}, editor = {Kampker, Achim and Heimes, Heiner Hans}, publisher = {Springer Vieweg}, address = {Berlin}, isbn = {978-3-662-65811-6 (Print)}, doi = {10.1007/978-3-662-65812-3_13}, pages = {227 -- 247}, year = {2023}, language = {de} } @book{JanserHavermannHoeveleretal.2023, author = {Janser, Frank and Havermann, Marc and Hoeveler, Bastian and Hertz, Cyril and Bergmann, Ole}, title = {Str{\"o}mungslehre und Aerodynamik : inkompressible Profile und Tragfl{\"u}gelaerodynamik, Band 2}, edition = {4. Auflage}, publisher = {Mainz}, address = {Aachen}, isbn = {978-3-8107-0261-6}, pages = {XIII, 211 Seiten}, year = {2023}, abstract = {Das vorliegende Buch dient als Grundlage f{\"u}r die Bachelor- und Master-Ausbildung von Studierenden im Fachgebiet Str{\"o}mungslehre und Aerodynamik. Im hier behandelten Teilbereich der inkompressiblen Profile und Tragfl{\"u}gelaerodynamik werden schwerpunktm{\"a}ßig die folgenden Themen besprochen: - Profilaerodynamik - Tragfl{\"u}gelaerodynamik - Flugzeugpolare - Methoden zur Flugbereichserweiterung - Schwebeschub und Schwebeleistung - Propellerblattaerodynamik - Numerische Methoden zur Tragfl{\"u}gelberechnung}, language = {de} } @incollection{DachwaldUlamecKowalskietal.2023, author = {Dachwald, Bernd and Ulamec, Stephan and Kowalski, Julia and Boxberg, Marc S. and Baader, Fabian and Biele, Jens and K{\"o}mle, Norbert}, title = {Ice melting probes}, series = {Handbook of Space Resources}, booktitle = {Handbook of Space Resources}, editor = {Badescu, Viorel and Zacny, Kris and Bar-Cohen, Yoseph}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-97912-6 (Print)}, doi = {10.1007/978-3-030-97913-3_29}, pages = {955 -- 996}, year = {2023}, abstract = {The exploration of icy environments in the solar system, such as the poles of Mars and the icy moons (a.k.a. ocean worlds), is a key aspect for understanding their astrobiological potential as well as for extraterrestrial resource inspection. On these worlds, ice melting probes are considered to be well suited for the robotic clean execution of such missions. In this chapter, we describe ice melting probes and their applications, the physics of ice melting and how the melting behavior can be modeled and simulated numerically, the challenges for ice melting, and the required key technologies to deal with those challenges. We also give an overview of existing ice melting probes and report some results and lessons learned from laboratory and field tests.}, language = {en} } @article{ThomaThomessenGardietal.2023, author = {Thoma, Andreas and Thomessen, Karolin and Gardi, Alessandro and Fisher, A. and Braun, Carsten}, title = {Prioritising paths: An improved cost function for local path planning for UAV in medical applications}, series = {The Aeronautical Journal}, journal = {The Aeronautical Journal}, number = {First View}, publisher = {Cambridge University Press}, address = {Cambridge}, issn = {0001-9240 (Print)}, doi = {10.1017/aer.2023.68}, pages = {1 -- 18}, year = {2023}, abstract = {Even the shortest flight through unknown, cluttered environments requires reliable local path planning algorithms to avoid unforeseen obstacles. The algorithm must evaluate alternative flight paths and identify the best path if an obstacle blocks its way. Commonly, weighted sums are used here. This work shows that weighted Chebyshev distances and factorial achievement scalarising functions are suitable alternatives to weighted sums if combined with the 3DVFH* local path planning algorithm. Both methods considerably reduce the failure probability of simulated flights in various environments. The standard 3DVFH* uses a weighted sum and has a failure probability of 50\% in the test environments. A factorial achievement scalarising function, which minimises the worst combination of two out of four objective functions, reaches a failure probability of 26\%; A weighted Chebyshev distance, which optimises the worst objective, has a failure probability of 30\%. These results show promise for further enhancements and to support broader applicability.}, language = {en} } @article{SchulzeFeyerlPischinger2023, author = {Schulze, Sven and Feyerl, G{\"u}nter and Pischinger, Stefan}, title = {Advanced ECMS for hybrid electric heavy-duty trucks with predictive battery discharge and adaptive operating strategy under real driving conditions}, series = {Energies}, volume = {16}, journal = {Energies}, number = {13}, publisher = {MDPI}, address = {Basel}, issn = {1996-1073}, doi = {10.3390/en16135171}, pages = {29 Seiten, Art. Nr.: 5171}, year = {2023}, abstract = {To fulfil the CO2 emission reduction targets of the European Union (EU), heavy-duty (HD) trucks need to operate 15\% more efficiently by 2025 and 30\% by 2030. Their electrification is necessary as conventional HD trucks are already optimized for the long-haul application. The resulting hybrid electric vehicle (HEV) truck gains most of the fuel saving potential by the recuperation of potential energy and its consecutive utilization. The key to utilizing the full potential of HEV-HD trucks is to maximize the amount of recuperated energy and ensure its intelligent usage while keeping the operating point of the internal combustion engine as efficient as possible. To achieve this goal, an intelligent energy management strategy (EMS) based on ECMS is developed for a parallel HEV-HD truck which uses predictive discharge of the battery and adaptive operating strategy regarding the height profile and the vehicle mass. The presented EMS can reproduce the global optimal operating strategy over long phases and lead to a fuel saving potential of up to 2\% compared with a heuristic strategy. Furthermore, the fuel saving potential is correlated with the investigated boundary conditions to deepen the understanding of the impact of intelligent EMS for HEV-HD trucks.}, language = {en} } @inproceedings{WeissAbanteribaEsch2007, author = {Weiss, Alexander and Abanteriba, Sylvester and Esch, Thomas}, title = {Investigation of Flow Separation Inside a Conical Rocket Nozzle With the Aid of an Annular Cross Flow}, series = {Proceedings of the ASME/JSME 2007 5th Joint Fluids Engineering Conference. Volume 1: Symposia, Parts A and B}, booktitle = {Proceedings of the ASME/JSME 2007 5th Joint Fluids Engineering Conference. Volume 1: Symposia, Parts A and B}, publisher = {American Society of Mechanical Engineers (ASME)}, address = {New York}, isbn = {0-7918-4288-6}, doi = {10.1115/FEDSM2007-37387}, pages = {1861 -- 1871}, year = {2007}, abstract = {Flow separation is a phenomenon that occurs in all kinds of supersonic nozzles sometimes during run-up and shut-down operations. Especially in expansion nozzles of rocket engines with large area ratio, flow separation can trigger strong side loads that can damage the structure of the nozzle. The investigation presented in this paper seeks to establish measures that may be applied to alter the point of flow separation. In order to achieve this, a supersonic nozzle was placed at the exit plane of the conical nozzle. This resulted in the generation of cross flow surrounding the core jet flow from the conical nozzle. Due to the entrainment of the gas stream from the conical nozzle the pressure in its exit plane was found to be lower than that of the ambient. A Cold gas instead of hot combustion gases was used as the working fluid. A mathematical simulation of the concept was validated by experiment. Measurements confirmed the simulation results that due to the introduction of a second nozzle the pressure in the separated region of the conical nozzle was significantly reduced. It was also established that the boundary layer separation inside the conical nozzle was delayed thus allowing an increased degree of overexpansion. The condition established by the pressure measurements was also demonstrated qualitatively using transparent nozzle configurations.}, language = {en} } @misc{PischingerEschDuesmann2006, author = {Pischinger, Martin and Esch, Thomas and Duesmann, Klaus}, title = {Elektromagnetischer Aktuator mit gelenkig abgest{\"u}tzter R{\"u}ckstellfeder}, year = {2006}, abstract = {Die Erfindung betrifft einen elektromagnetischen Aktuator zur Bet{\"a}tigung eines Stellgliedes (7) mit wenigstens einem gesteuert bestrombaren Elektromagneten (1, 2) und einem mit dem Stellglied (7) in Wirkverbindung stehenden Anker (5), der bei Bestromung des Elektromagneten (1, 2) gegen die Kraft wenigstens einer an einem Geh{\"a}use (12) abgest{\"u}tzten R{\"u}ckstellfeder (10) an der Polfl{\"a}che (3, 4) des Elektromagneten (1, 2) zur Anlage kommt, und daß zumindest der Anker (5) {\"u}ber eine sph{\"a}rische Gelenkanordnung (11) auf der R{\"u}ckstellfeder (10) abgest{\"u}tzt ist.}, language = {de} } @inproceedings{HuthElsenHartwigetal.2006, author = {Huth, Thomas and Elsen, Olaf and Hartwig, Christoph and Esch, Thomas}, title = {Innovative modular valve trains for 2015 - logistic benefits by EMVT}, series = {IFAC Proceedings Volumes, Volume 39, Issue 3}, booktitle = {IFAC Proceedings Volumes, Volume 39, Issue 3}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.3182/20060517-3-FR-2903.00172}, pages = {315 -- 320}, year = {2006}, abstract = {In this paper the way to a 5-day-car with respect to a modular valve train systems for spark ignited combustion engines is shown. The necessary product diversity is shift from mechanical or physical components to software components. Therefore, significant improvements of logistic indicators are expected and shown. The working principle of a camless cylinder head with respect to an electromagnetical valve train (EMVT) is explained and it is demonstrated that shifting physical diversity to software is feasible. The future design of combustion engine systems including customisation can be supported by a set of assistance tools which is shown exemplary.}, language = {en} } @misc{SchmitzSchebitzEsch1997, author = {Schmitz, G{\"u}nter and Schebitz, Michael and Esch, Thomas}, title = {Aus der Ruhelage selbstanziehender elektromagnetischer Aktuator}, year = {1997}, abstract = {Elektromagnetischer Aktuator zur Bet{\"a}tigung eines Stellgliedes (2), mit wenigstens einem Elektromagneten (4) und einem mit dem Stellglied (2) verbundenen Anker (3), der gegen die Kraft einer R{\"u}ckstellfeder (6) aus seiner Ruhelage in Richtung auf den Elektromagneten (4) bewegbar ist, mit einer R{\"u}ckstellfeder (6), die eine nicht lineare, bezogen auf die Ruhelage des Ankers (3) progressiv ansteigende Kennlinie aufweist.}, language = {de} } @misc{SalberPischingerEschetal.1998, author = {Salber, Wolfgang and Pischinger, Martin and Esch, Thomas and Hagen, J{\"u}rgen}, title = {Kaltstartverfahren f{\"u}r eine drosselfreie Mehrzylinder-Kolbenbrennkraftmaschine}, year = {1998}, abstract = {Die Erfindung betrifft ein Kaltstartverfahren f{\"u}r eine Mehrzylinder-Kolbenbrennkraftmaschine mit Anlasser und einer Motorsteuerung zur Ansteuerung von Kraftstoffeinspritzeinrichtungen, Z{\"u}ndung und voll variabel elektromagnetisch bet{\"a}tigbaren Gaswechselventilen an den einzelnen Zylindern, bei dem die Kurbelwelle {\"u}ber den Anlasser gedreht wird und zum Start f{\"u}r wenigstens einen Zylinder die dazugeh{\"o}rigen Gaswechselventile, die Kraftstoffeinspritzeinrichtung und die Z{\"u}ndung in einem vorgegebenen Taktzyklus angesteuert werden und zwar in den ersten Arbeitszyklen mit "Sp{\"a}tem Einlaß {\"O}ffnen".}, language = {de} } @article{BaaderBoxbergChenetal.2023, author = {Baader, Fabian and Boxberg, Marc S. and Chen, Qian and F{\"o}rstner, Roger and Kowalski, Julia and Dachwald, Bernd}, title = {Field-test performance of an ice-melting probe in a terrestrial analogue environment}, series = {Icarus}, journal = {Icarus}, number = {409}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.icarus.2023.115852}, pages = {Artikel 115852}, year = {2023}, abstract = {Melting probes are a proven tool for the exploration of thick ice layers and clean sampling of subglacial water on Earth. Their compact size and ease of operation also make them a key technology for the future exploration of icy moons in our Solar System, most prominently Europa and Enceladus. For both mission planning and hardware engineering, metrics such as efficiency and expected performance in terms of achievable speed, power requirements, and necessary heating power have to be known. Theoretical studies aim at describing thermal losses on the one hand, while laboratory experiments and field tests allow an empirical investigation of the true performance on the other hand. To investigate the practical value of a performance model for the operational performance in extraterrestrial environments, we first contrast measured data from terrestrial field tests on temperate and polythermal glaciers with results from basic heat loss models and a melt trajectory model. For this purpose, we propose conventions for the determination of two different efficiencies that can be applied to both measured data and models. One definition of efficiency is related to the melting head only, while the other definition considers the melting probe as a whole. We also present methods to combine several sources of heat loss for probes with a circular cross-section, and to translate the geometry of probes with a non-circular cross-section to analyse them in the same way. The models were selected in a way that minimizes the need to make assumptions about unknown parameters of the probe or the ice environment. The results indicate that currently used models do not yet reliably reproduce the performance of a probe under realistic conditions. Melting velocities and efficiencies are constantly overestimated by 15 to 50 \% in the models, but qualitatively agree with the field test data. Hence, losses are observed, that are not yet covered and quantified by the available loss models. We find that the deviation increases with decreasing ice temperature. We suspect that this mismatch is mainly due to the too restrictive idealization of the probe model and the fact that the probe was not operated in an efficiency-optimized manner during the field tests. With respect to space mission engineering, we find that performance and efficiency models must be used with caution in unknown ice environments, as various ice parameters have a significant effect on the melting process. Some of these are difficult to estimate from afar.}, language = {en} } @misc{FeldmannFranckeEspeetal.2022, author = {Feldmann, Marco and Francke, Gero and Espe, Clemes and Chen, Qian and Baader, Fabian and Boxberg, Marc S. and Sustrate, Anna-Marie and Kowalski, Julia and Dachwald, Bernd}, title = {Performance data of an ice-melting probe from field tests in two different ice environments}, doi = {10.5281/zenodo.6094866}, year = {2022}, abstract = {This dataset was acquired at field tests of the steerable ice-melting probe "EnEx-IceMole" (Dachwald et al., 2014). A field test in summer 2014 was used to test the melting probe's system, before the probe was shipped to Antarctica, where, in international cooperation with the MIDGE project, the objective of a sampling mission in the southern hemisphere summer 2014/2015 was to return a clean englacial sample from the subglacial brine reservoir supplying the Blood Falls at Taylor Glacier (Badgeley et al., 2017, German et al., 2021). The standardized log-files generated by the IceMole during melting operation include more than 100 operational parameters, housekeeping information, and error states, which are reported to the base station in intervals of 4 s. Occasional packet loss in data transmission resulted in a sparse number of increased sampling intervals, which where compensated for by linear interpolation during post processing. The presented dataset is based on a subset of this data: The penetration distance is calculated based on the ice screw drive encoder signal, providing the rate of rotation, and the screw's thread pitch. The melting speed is calculated from the same data, assuming the rate of rotation to be constant over one sampling interval. The contact force is calculated from the longitudinal screw force, which es measured by strain gauges. The used heating power is calculated from binary states of all heating elements, which can only be either switched on or off. Temperatures are measured at each heating element and averaged for three zones (melting head, side-wall heaters and back-plate heaters).}, language = {en} } @article{FunkeBeckmann2022, author = {Funke, Harald and Beckmann, Nils}, title = {Flexible fuel operation of a Dry-Low-NOx Micromix Combustor with Variable Hydrogen Methane Mixture}, series = {International Journal of Gas Turbine, Propulsion and Power Systems}, volume = {13}, journal = {International Journal of Gas Turbine, Propulsion and Power Systems}, number = {2}, issn = {1882-5079}, pages = {1 -- 7}, year = {2022}, abstract = {The role of hydrogen (H2) as a carbon-free energy carrier is discussed since decades for reducing greenhouse gas emissions. As bridge technology towards a hydrogen-based energy supply, fuel mixtures of natural gas or methane (CH4) and hydrogen are possible. The paper presents the first test results of a low-emission Micromix combustor designed for flexible-fuel operation with variable H2/CH4 mixtures. The numerical and experimental approach for considering variable fuel mixtures instead of recently investigated pure hydrogen is described. In the experimental studies, a first generation FuelFlex Micromix combustor geometry is tested at atmospheric pressure at gas turbine operating conditions corresponding to part- and full-load. The H2/CH4 fuel mixture composition is varied between 57 and 100 vol.\% hydrogen content. Despite the challenges flexible-fuel operation poses onto the design of a combustion system, the evaluated FuelFlex Micromix prototype shows a significant low NOx performance}, language = {en} } @article{KochBoehnischVerdoncketal.2024, author = {Koch, Christopher and B{\"o}hnisch, Nils and Verdonck, Hendrik and Hach, Oliver and Braun, Carsten}, title = {Comparison of unsteady low- and mid-fidelity propeller aerodynamic methods for whirl flutter applications}, series = {Applied Sciences}, volume = {14}, journal = {Applied Sciences}, number = {2}, publisher = {MDPI}, address = {Basel}, issn = {2076-3417}, doi = {10.3390/app14020850}, pages = {1 -- 28}, year = {2024}, abstract = {Aircraft configurations with propellers have been drawing more attention in recent times, partly due to new propulsion concepts based on hydrogen fuel cells and electric motors. These configurations are prone to whirl flutter, which is an aeroelastic instability affecting airframes with elastically supported propellers. It commonly needs to be mitigated already during the design phase of such configurations, requiring, among other things, unsteady aerodynamic transfer functions for the propeller. However, no comprehensive assessment of unsteady propeller aerodynamics for aeroelastic analysis is available in the literature. This paper provides a detailed comparison of nine different low- to mid-fidelity aerodynamic methods, demonstrating their impact on linear, unsteady aerodynamics, as well as whirl flutter stability prediction. Quasi-steady and unsteady methods for blade lift with or without coupling to blade element momentum theory are evaluated and compared to mid-fidelity potential flow solvers (UPM and DUST) and classical, derivative-based methods. Time-domain identification of frequency-domain transfer functions for the unsteady propeller hub loads is used to compare the different methods. Predictions of the minimum required pylon stiffness for stability show good agreement among the mid-fidelity methods. The differences in the stability predictions for the low-fidelity methods are higher. Most methods studied yield a more unstable system than classical, derivative-based whirl flutter analysis, indicating that the use of more sophisticated aerodynamic modeling techniques might be required for accurate whirl flutter prediction.}, language = {en} } @inproceedings{FunkeBeckmannStefanetal.2023, author = {Funke, Harald and Beckmann, Nils and Stefan, Lukas and Keinz, Jan}, title = {Hydrogen combustor integration study for a medium range aircraft engine using the dry-low NOx "Micromix" combustion principle}, series = {Proceedings of the ASME Turbo Expo 2023: Turbomachinery Technical Conference and Exposition. Volume 1: Aircraft Engine.}, booktitle = {Proceedings of the ASME Turbo Expo 2023: Turbomachinery Technical Conference and Exposition. Volume 1: Aircraft Engine.}, publisher = {ASME}, address = {New York}, isbn = {978-0-7918-8693-9}, doi = {10.1115/GT2023-102370}, pages = {12 Seiten}, year = {2023}, abstract = {The feasibility study presents results of a hydrogen combustor integration for a Medium-Range aircraft engine using the Dry-Low-NOₓ Micromix combustion principle. Based on a simplified Airbus A320-type flight mission, a thermodynamic performance model of a kerosene and a hydrogen-powered V2530-A5 engine is used to derive the thermodynamic combustor boundary conditions. A new combustor design using the Dry-Low NOx Micromix principle is investigated by slice model CFD simulations of a single Micromix injector for design and off-design operation of the engine. Combustion characteristics show typical Micromix flame shapes and good combustion efficiencies for all flight mission operating points. Nitric oxide emissions are significant below ICAO CAEP/8 limits. For comparison of the Emission Index (EI) for NOₓ emissions between kerosene and hydrogen operation, an energy (kerosene) equivalent Emission Index is used. A full 15° sector model CFD simulation of the combustion chamber with multiple Micromix injectors including inflow homogenization and dilution and cooling air flows investigates the combustor integration effects, resulting NOₓ emission and radial temperature distributions at the combustor outlet. The results show that the integration of a Micromix hydrogen combustor in actual aircraft engines is feasible and offers, besides CO₂ free combustion, a significant reduction of NOₓ emissions compared to kerosene operation.}, language = {en} } @inproceedings{GehlerOberBloebaumDachwald2009, author = {Gehler, M. and Ober-Bl{\"o}baum, S. and Dachwald, Bernd}, title = {Application of discrete mechanics and optimal control to spacecraft in non-keplerian motion around small solar system bodies}, series = {Procceedings of the 60th International Astronautical Congress}, booktitle = {Procceedings of the 60th International Astronautical Congress}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {978-161567908-9}, pages = {1360 -- 1371}, year = {2009}, abstract = {Prolonged operations close to small solar system bodies require a sophisticated control logic to minimize propellant mass and maximize operational efficiency. A control logic based on Discrete Mechanics and Optimal Control (DMOC) is proposed and applied to both conventionally propelled and solar sail spacecraft operating at an arbitrarily shaped asteroid in the class of Itokawa. As an example, stand-off inertial hovering is considered, recently identified as a challenging part of the Marco Polo mission. The approach is easily extended to stand-off orbits. We show that DMOC is applicable to spacecraft control at small objects, in particular with regard to the fact that the changes in gravity are exploited by the algorithm to optimally control the spacecraft position. Furthermore, we provide some remarks on promising developments.}, language = {en} } @inproceedings{DachwaldWurm2009, author = {Dachwald, Bernd and Wurm, P.}, title = {Design concept and modeling of an advanced solar photon thruster}, series = {Advances in the Astronautical Sciences}, booktitle = {Advances in the Astronautical Sciences}, publisher = {American Astronautical Society}, address = {San Diego, Calif.}, isbn = {978-087703554-1}, issn = {00653438}, pages = {723 -- 740}, year = {2009}, abstract = {The so-called "compound solar sail", also known as "Solar Photon Thruster" (SPT), holds the potential of providing significant performance advantages over the flat solar sail. Previous SPT design concepts, however, do not consider shadowing effects and multiple reflections of highly concentrated solar radiation that would inevitably destroy the gossamer sail film. In this paper, we propose a novel advanced SPT (ASPT) design concept that does not suffer from these oversimplifications. We present the equations that describe the thrust force acting on such a sail system and compare its performance with respect to the conventional flat solar sail.}, language = {en} } @incollection{Dachwald2017, author = {Dachwald, Bernd}, title = {Light propulsion systems for spacecraft}, series = {Optical nano and micro actuator technology}, booktitle = {Optical nano and micro actuator technology}, editor = {Knopf, George K. and Otani, Yukitoshi}, publisher = {CRC Press}, address = {Boca Raton}, isbn = {9781315217628 (eBook)}, pages = {577 -- 598}, year = {2017}, language = {en} }