TY - CHAP A1 - Hallmann, Marcus A1 - Heidecker, Ansgar A1 - Schlotterer, Markus A1 - Dachwald, Bernd T1 - GTOC8: results and methods of team 15 DLR T2 - 26th AAS/AIAA Space Flight Mechanics Meeting, Napa, CA N2 - This paper describes the results and methods used during the 8th Global Trajectory Optimization Competition (GTOC) of the DLR team. Trajectory optimization is crucial for most of the space missions and usually can be formulated as a global optimization problem. A lot of research has been done to different type of mission problems. The most demanding ones are low thrust transfers with e.g. gravity assist sequences. In that case the optimal control problem is combined with an integer problem. In most of the GTOCs we apply a filtering of the problem based on domain knowledge. Y1 - 2016 N1 - 26th AAS/AIAA Space Flight Mechanics Meeting, February 14-18, 2016, Napa, California, U.S.A. Napa, CA ER - TY - CHAP A1 - Duprat, J. A1 - Dachwald, Bernd A1 - Hilchenbach, M. A1 - Engrand, Cecile A1 - Espe, C. A1 - Feldmann, M. A1 - Francke, G. A1 - Görög, Mark A1 - Lüsing, N. A1 - Langenhorst, Falko T1 - The MARVIN project: a micrometeorite harvester in Antarctic snow T2 - 44th Lunar and Planetary Science Conference N2 - MARVIN is an automated drilling and melting probe dedicated to collect pristine interplanetary dust particles (micrometeorites) from central Antarctica snow. Y1 - 2013 N1 - 44th Lunar and Planetary Science Conference, March 18-22, 2013, The Woodlands, Texas ER - TY - CHAP A1 - Dachwald, Bernd A1 - Seboldt, Wolfgang A1 - Loeb, Horst W. A1 - Schartner, Karl-Heinz T1 - A comparison of SEP and NEP for a main belt asteroid sample return mission T2 - 7th International Symposium on Launcher Technologies, Barcelona, Spain, 02-05 April 2007 N2 - Innovative interplanetary deep space missions, like a main belt asteroid sample return mission, require ever larger velocity increments (∆V s) and thus ever more demanding propulsion capabilities. Providing much larger exhaust velocities than chemical high-thrust systems, electric low-thrust space-propulsion systems can significantly enhance or even enable such high-energy missions. In 1995, a European-Russian Joint Study Group (JSG) presented a study report on “Advanced Interplanetary Missions Using Nuclear-Electric Propulsion” (NEP). One of the investigated reference missions was a sample return (SR) from the main belt asteroid (19) Fortuna. The envisaged nuclear power plant, Topaz-25, however, could not be realized and also the worldwide developments in space reactor hardware stalled. In this paper, we investigate, whether such a mission is also feasible using a solar electric propulsion (SEP) system and compare our SEP results to corresponding NEP results. Y1 - 2007 SP - 1 EP - 10 ER - TY - CHAP A1 - Dachwald, Bernd T1 - Global optimization of low-thrust space missions using evolutionary neurocontrol T2 - Proceedings of the international workshop on global optimization N2 - Low-thrust space propulsion systems enable flexible high-energy deep space missions, but the design and optimization of the interplanetary transfer trajectory is usually difficult. It involves much experience and expert knowledge because the convergence behavior of traditional local trajectory optimization methods depends strongly on an adequate initial guess. Within this extended abstract, evolutionary neurocontrol, a method that fuses artificial neural networks and evolutionary algorithms, is proposed as a smart global method for low-thrust trajectory optimization. It does not require an initial guess. The implementation of evolutionary neurocontrol is detailed and its performance is shown for an exemplary mission. KW - Evolutionary Neurocontrol KW - Spacecraft Trajectory Optimization KW - Low-Thrust Propulsion Y1 - 2005 SP - 85 EP - 90 ER - TY - CHAP A1 - Dachwald, Bernd A1 - Baturkin, Volodymyr A1 - Coverstone, Victoria A1 - Diedrich, Ben A1 - Garbe, Gregory A1 - Görlich, Marianne A1 - Leipold, Manfred A1 - Lura, Franz A1 - Macdonald, Malcolm A1 - McInnes, Colin A1 - Mengali, Giovanni A1 - Quarta, Alessandro A1 - Rios-Reyes, Leonel A1 - Scheeres, Daniel J. A1 - Seboldt, Wolfgang A1 - Wie, Bong T1 - Potential effects of optical solar sail degredation on trajectory design T2 - AAS/AIAA Astrodynamics Specialist N2 - The optical properties of the thin metalized polymer films that are projected for solar sails are assumed to be affected by the erosive effects of the space environment. Their degradation behavior in the real space environment, however, is to a considerable degree indefinite, because initial ground test results are controversial and relevant inspace tests have not been made so far. The standard optical solar sail models that are currently used for trajectory design do not take optical degradation into account, hence its potential effects on trajectory design have not been investigated so far. Nevertheless, optical degradation is important for high-fidelity solar sail mission design, because it decreases both the magnitude of the solar radiation pressure force acting on the sail and also the sail control authority. Therefore, we propose a simple parametric optical solar sail degradation model that describes the variation of the sail film’s optical coefficients with time, depending on the sail film’s environmental history, i.e., the radiation dose. The primary intention of our model is not to describe the exact behavior of specific film-coating combinations in the real space environment, but to provide a more general parametric framework for describing the general optical degradation behavior of solar sails. Using our model, the effects of different optical degradation behaviors on trajectory design are investigated for various exemplary missions. Y1 - 2005 N1 - 2005 AAS/AIAA Astrodynamics Specialist Conference, 7-11.08.2005. Lake Tahoe, California https://www.space-flight.org/AAS_meetings/2005_astro/2005_astro.html SP - 1 EP - 23 ER - TY - CHAP A1 - Hebel, Christoph A1 - Herrmann, Ulf A1 - Ritz, Thomas A1 - Röth, Thilo A1 - Anthrakidis, Anette A1 - Böker, Jörg A1 - Franzke, Till A1 - Grodzki, Thomas A1 - Merkens, Torsten A1 - Schöttler, Mirjam T1 - FlexSHARE – Methodisches Framework zur innovativen Gestaltung der urbanen Mobilität durch Sharing- Angebote T2 - Transforming Mobility – What Next? N2 - Das Ziel des INTERREG-Projektes „SHAREuregio“ (FKZ: 34.EFRE-0300134) ist es, grenzüberschreitende Mobilität in der Euregio Rhein-Maas-Nord zu ermöglichen und zu fördern. Dazu soll ein elektromobiles Car- und Bikesharing- System entwickelt und in der Stadt Mönchengladbach, im Kreis Viersen sowie in den Gemeinden Roermond und Venlo (beide NL) zusammen mit den Partnern Wirtschaftsförderung Mönchengladbach, Wirtschaftsförderung für den Kreis Viersen, NEW AG, Goodmoovs (NL), Greenflux (NL) und der FH Aachen implementiert werden. Zunächst richtet sich das Angebot, bestehend aus 40 Elektroautos und 40 Elektrofahrrädern, an Unternehmen und wird nach einer Erprobungsphase, mit einer größeren Anzahl an Fahrzeugen, auch für Privatpersonen verfügbar gemacht werden. Die Fahrzeuge stehen bei den jeweiligen Anwendungspartnern in Deutschland und den Niederlanden. Im Rahmen dieses Projektes hat die FH Aachen „FlexSHARE“ entwickelt – ein methodisches Framework zur innovativen Gestaltung urbaner Sharing- Angebote. Das Framework ermöglicht es, anhand von messbaren Kenngrößen, bedarfsgerechte und auf die Region abgestimmte Sharing-Systeme zu entwickeln. Y1 - 2022 SN - 978-3-658-36429-8 U6 - http://dx.doi.org/10.1007/978-3-658-36430-4_10 N1 - Tagungsband zum 13. Wissenschaftsforum Mobilität, Beiträge des Wissenschaftsforums SP - 153 EP - 169 PB - Springer Gabler CY - Wiesbaden ER - TY - CHAP A1 - Bauschat, J.-Michael A1 - Benner, Miriam A1 - Klinge, Henner A1 - Ziegler, Simon T1 - Urbane Mobilität entdeckt die 3. Dimension T2 - Transforming Mobility – What Next? N2 - Der Themenkomplex urbane Mobilität ist getrieben durch den Verkehrsinfarkt in Ballungszentren, durch Luftverschmutzung und Lärm, sowie den Trend zum Leben in der Stadt in den städteplanerischen Fokus gerückt. Emissionsneutrale Antriebskonzepte in der Luftfahrt führen zu Ansätzen Fluggeräte einzusetzen, die batteriegetrieben vertikal aufsteigen und landen können. Flugphysikalisch und energetisch ist diese Technik nur dann sinnvoll, wenn es zwingende Gründe gibt (z.B. Rettungseinsätze), daher wird der flugphysikalische Hintergrund prinzipiell erläutert. Es werden einige aktuelle Lufttransportkonzepte für eine urbane Personenbeförderung vorgestellt. Sollte es verstärkt zu Lufttransport über Städten kommen, müssen betroffene Lufträume geordnet und überwacht werden. Wie kompatibel Lufttransportsysteme mit den heute bereits relevanten urbanen Beförderungsmitteln sein müssen, wird kritisch diskutiert. Abschließend werden die Aspekte Akzeptanz durch die Kunden und Wirtschaftlichkeit ebenso angerissen, wie die hochproblematische Rohstoffgewinnung, die Entsorgung und das Recycling von Batterien. Y1 - 2022 SN - 978-3-658-36429-8 U6 - http://dx.doi.org/10.1007/978-3-658-36430-4_53 N1 - Tagungsband zum 13. Wissenschaftsforum Mobilität, Beiträge des Wissenschaftsforums SP - 895 EP - 916 PB - Springer Gabler CY - Wiesbaden ER - TY - JOUR A1 - Bergmann, Ole A1 - Möhren, Felix A1 - Braun, Carsten A1 - Janser, Frank T1 - On the influence of elasticity on swept propeller noise JF - AIAA SCITECH 2023 Forum N2 - High aerodynamic efficiency requires propellers with high aspect ratios, while propeller sweep potentially reduces noise. Propeller sweep and high aspect ratios increase elasticity and coupling of structural mechanics and aerodynamics, affecting the propeller performance and noise. Therefore, this paper analyzes the influence of elasticity on forward-swept, backward-swept, and unswept propellers in hover conditions. A reduced-order blade element momentum approach is coupled with a one-dimensional Timoshenko beam theory and Farassat's formulation 1A. The results of the aeroelastic simulation are used as input for the aeroacoustic calculation. The analysis shows that elasticity influences noise radiation because thickness and loading noise respond differently to deformations. In the case of the backward-swept propeller, the location of the maximum sound pressure level shifts forward by 0.5 °, while in the case of the forward-swept propeller, it shifts backward by 0.5 °. Therefore, aeroacoustic optimization requires the consideration of propeller deformation. Y1 - 2023 U6 - http://dx.doi.org/10.2514/6.2023-0210 N1 - Session: Propeller, Open Rotor, and Rotorcraft Noise II AIAA SCITECH 2023 Forum, 23-27 January 2023, National Harbor, MD & Online PB - AIAA ER - TY - CHAP A1 - Hille, Sebastian A1 - Stumpf, Eike A1 - Mayntz, Joscha A1 - Dahmann, Peter T1 - Prediction of sound exposure caused by a landing motor glider with recuperating propellers T2 - AIAA SCITECH 2023 Forum N2 - This paper presents an approach to predicting the sound exposure on the ground caused by a landing aircraft with recuperating propellers. The noise source along the trajectory of a flight specified for a steeper approach is simulated based on measurements of sound power levels and additional parameters of a single propeller placed in a wind tunnel. To validate the measured data/measurement results, these simulations are also supported by overflight measurements of a test aircraft. It is shown that the simple source models of propellers do not provide fully satisfactory results since the sound levels are estimated too low. Nevertheless, with a further reference comparison, margins for an acceptable increase in the sound power level of the aircraft on its now steeper approach path could be estimated. Thus, in this case, a +7 dB increase in SWL would not increase the SEL compared to the conventional approach within only 2 km ahead of the airfield. Y1 - 2023 U6 - http://dx.doi.org/10.2514/6.2023-0211 N1 - AIAA SCITECH 2023 Forum, 23-27 January 2023, National Harbor, MD & Online PB - AIAA ER - TY - CHAP A1 - Horikawa, Atsushi A1 - Ashikaga, Mitsugu A1 - Yamaguchi, Masato A1 - Ogino, Tomoyuki A1 - Aoki, Shigeki A1 - Wirsum, Manfred A1 - Funke, Harald A1 - Kusterer, Karsten T1 - Combined heat and power supply demonstration of Micro-Mix Hydrogen Combustion Applied to M1A-17 Gas Turbine T2 - Proceedings of ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition (GT2022) (Volume 3A) N2 - Kawasaki Heavy Industries, Ltd. (KHI), Aachen University of Applied Sciences, and B&B-AGEMA GmbH have investigated the potential of low NOx micro-mix (MMX) hydrogen combustion and its application to an industrial gas turbine combustor. Engine demonstration tests of a MMX combustor for the M1A-17 gas turbine with a co-generation system were conducted in the hydrogen-fueled power generation plant in Kobe City, Japan. This paper presents the results of the commissioning test and the combined heat and power (CHP) supply demonstration. In the commissioning test, grid interconnection, loading tests and load cut-off tests were successfully conducted. All measurement results satisfied the Japanese environmental regulation values. Dust and soot as well as SOx were not detected. The NOx emissions were below 84 ppmv at 15 % O2. The noise level at the site boundary was below 60 dB. The vibration at the site boundary was below 45 dB. During the combined heat and power supply demonstration, heat and power were supplied to neighboring public facilities with the MMX combustion technology and 100 % hydrogen fuel. The electric power output reached 1800 kW at which the NOx emissions were 72 ppmv at 15 % O2, and 60 %RH. Combustion instabilities were not observed. The gas turbine efficiency was improved by about 1 % compared to a non-premixed type combustor with water injection as NOx reduction method. During a total equivalent operation time of 1040 hours, all combustor parts, the M1A-17 gas turbine as such, and the co-generation system were without any issues. KW - industrial gas turbine KW - combustor development KW - fuels KW - hydrogen KW - emission Y1 - 2022 SN - 978-0-7918-8599-4 U6 - http://dx.doi.org/10.1115/GT2022-81620 N1 - ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition June 13–17, 2022 Rotterdam, Netherlands PB - American Society of Mechanical Engineers CY - Fairfield ER -