@inproceedings{PirovanoSeefeldtDachwaldetal.2015, author = {Pirovano, Laura and Seefeldt, Patric and Dachwald, Bernd and Noomen, Ron}, title = {Attitude and orbital modeling of an uncontrolled solar-sail experiment in low-Earth orbit}, series = {25th International Symposium on Space Flight Dynamics ISSFD}, booktitle = {25th International Symposium on Space Flight Dynamics ISSFD}, pages = {1 -- 15}, year = {2015}, abstract = {Gossamer-1 is the first project of the three-step Gossamer roadmap, the purpose of which is to develop, prove and demonstrate that solar-sail technology is a safe and reliable propulsion technique for long-lasting and high-energy missions. This paper firstly presents the structural analysis performed on the sail to understand its elastic behavior. The results are then used in attitude and orbital simulations. The model considers the main forces and torques that a satellite experiences in low-Earth orbit coupled with the sail deformation. Doing the simulations for varying initial conditions in attitude and rotation rate, the results show initial states to avoid and maximum rotation rates reached for correct and faulty deployment of the sail. Lastly comparisons with the classic flat sail model are carried out to test the hypothesis that the elastic behavior does play a role in the attitude and orbital behavior of the sail}, language = {en} } @inproceedings{DachwaldKahleWie2006, author = {Dachwald, Bernd and Kahle, Ralph and Wie, Bong}, title = {Solar sail Kinetic Energy Impactor (KEI) mission design tradeoffs for impacting and deflecting asteroid 99942 Apophis}, series = {AIAA/AAS Astrodynamics Specialist Conference and Exhibit}, booktitle = {AIAA/AAS Astrodynamics Specialist Conference and Exhibit}, doi = {10.2514/6.2006-6178}, pages = {1 -- 20}, year = {2006}, abstract = {Near-Earth asteroid 99942 Apophis provides a typical example for the evolution of asteroid orbits that lead to Earth-impacts after a close Earth-encounter that results in a resonant return. Apophis will have a close Earth-encounter in 2029 with potential very close subsequent Earth-encounters (or even an impact) in 2036 or later, depending on whether it passes through one of several so-called gravitational keyholes during its 2029-encounter. Several pre-2029-deflection scenarios to prevent Apophis from doing this have been investigated so far. Because the keyholes are less than 1 km in size, a pre-2029 kinetic impact is clearly the best option because it requires only a small change in Apophis' orbit to nudge it out of a keyhole. A single solar sail Kinetic Energy Impactor (KEI) spacecraft that impacts Apophis from a retrograde trajectory with a very high relative velocity (75-80 km/s) during one of its perihelion passages at about 0.75 AU would be a feasible option to do this. The spacecraft consists of a 160 m x 160 m, 168 kg solar sail assembly and a 150 kg impactor. Although conventional spacecraft can also achieve the required minimum deflection of 1 km for this approx. 320 m-sized object from a prograde trajectory, our solar sail KEI concept also allows the deflection of larger objects. In this paper, we also show that, even after Apophis has flown through one of the gravitational keyholes in 2029, solar sail Kinetic Energy Impactor (KEI) spacecraft are still a feasible option to prevent Apophis from impacting the Earth, but many KEIs would be required for consecutive impacts to increase the total Earth-miss distance to a safe value. In this paper, we elaborate potential pre- and post-2029 KEI impact scenarios for a launch in 2020, and investigate tradeoffs between different mission parameters.}, language = {en} } @inproceedings{HallmannHeideckerSchlottereretal.2016, author = {Hallmann, Marcus and Heidecker, Ansgar and Schlotterer, Markus and Dachwald, Bernd}, title = {GTOC8: results and methods of team 15 DLR}, series = {26th AAS/AIAA Space Flight Mechanics Meeting, Napa, CA}, booktitle = {26th AAS/AIAA Space Flight Mechanics Meeting, Napa, CA}, year = {2016}, abstract = {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.}, language = {en} } @inproceedings{DupratDachwaldHilchenbachetal.2013, author = {Duprat, J. and Dachwald, Bernd and Hilchenbach, M. and Engrand, Cecile and Espe, C. and Feldmann, M. and Francke, G. and G{\"o}r{\"o}g, Mark and L{\"u}sing, N. and Langenhorst, Falko}, title = {The MARVIN project: a micrometeorite harvester in Antarctic snow}, series = {44th Lunar and Planetary Science Conference}, booktitle = {44th Lunar and Planetary Science Conference}, year = {2013}, abstract = {MARVIN is an automated drilling and melting probe dedicated to collect pristine interplanetary dust particles (micrometeorites) from central Antarctica snow.}, language = {en} } @inproceedings{DachwaldSeboldtLoebetal.2007, author = {Dachwald, Bernd and Seboldt, Wolfgang and Loeb, Horst W. and Schartner, Karl-Heinz}, title = {A comparison of SEP and NEP for a main belt asteroid sample return mission}, series = {7th International Symposium on Launcher Technologies, Barcelona, Spain, 02-05 April 2007}, booktitle = {7th International Symposium on Launcher Technologies, Barcelona, Spain, 02-05 April 2007}, pages = {1 -- 10}, year = {2007}, abstract = {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.}, language = {en} } @inproceedings{Dachwald2005, author = {Dachwald, Bernd}, title = {Global optimization of low-thrust space missions using evolutionary neurocontrol}, series = {Proceedings of the international workshop on global optimization}, booktitle = {Proceedings of the international workshop on global optimization}, pages = {85 -- 90}, year = {2005}, abstract = {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.}, language = {en} } @inproceedings{DachwaldBaturkinCoverstoneetal.2005, author = {Dachwald, Bernd and Baturkin, Volodymyr and Coverstone, Victoria and Diedrich, Ben and Garbe, Gregory and G{\"o}rlich, Marianne and Leipold, Manfred and Lura, Franz and Macdonald, Malcolm and McInnes, Colin and Mengali, Giovanni and Quarta, Alessandro and Rios-Reyes, Leonel and Scheeres, Daniel J. and Seboldt, Wolfgang and Wie, Bong}, title = {Potential effects of optical solar sail degredation on trajectory design}, series = {AAS/AIAA Astrodynamics Specialist}, booktitle = {AAS/AIAA Astrodynamics Specialist}, pages = {1 -- 23}, year = {2005}, abstract = {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.}, language = {en} } @inproceedings{HilleStumpfMayntzetal.2023, author = {Hille, Sebastian and Stumpf, Eike and Mayntz, Joscha and Dahmann, Peter}, title = {Prediction of sound exposure caused by a landing motor glider with recuperating propellers}, series = {AIAA SCITECH 2023 Forum}, booktitle = {AIAA SCITECH 2023 Forum}, publisher = {AIAA}, doi = {10.2514/6.2023-0211}, year = {2023}, abstract = {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.}, language = {en} } @inproceedings{HorikawaAshikagaYamaguchietal.2022, author = {Horikawa, Atsushi and Ashikaga, Mitsugu and Yamaguchi, Masato and Ogino, Tomoyuki and Aoki, Shigeki and Wirsum, Manfred and Funke, Harald and Kusterer, Karsten}, title = {Combined heat and power supply demonstration of Micro-Mix Hydrogen Combustion Applied to M1A-17 Gas Turbine}, series = {Proceedings of ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition (GT2022) (Volume 3A)}, booktitle = {Proceedings of ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition (GT2022) (Volume 3A)}, publisher = {American Society of Mechanical Engineers}, address = {Fairfield}, isbn = {978-0-7918-8599-4}, doi = {10.1115/GT2022-81620}, pages = {7 Seiten}, year = {2022}, abstract = {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.}, language = {en} } @inproceedings{MoehrenBergmannJanseretal.2023, author = {M{\"o}hren, Felix and Bergmann, Ole and Janser, Frank and Braun, Carsten}, title = {On the determination of harmonic propeller loads}, series = {AIAA SCITECH 2023 Forum}, booktitle = {AIAA SCITECH 2023 Forum}, publisher = {AIAA}, doi = {10.2514/6.2023-2404}, pages = {12 Seiten}, year = {2023}, abstract = {Dynamic loads significantly impact the structural design of propeller blades due to fatigue and static strength. Since propellers are elastic structures, deformations and aerodynamic loads are coupled. In the past, propeller manufacturers established procedures to determine unsteady aerodynamic loads and the structural response with analytical steady-state calculations. According to the approach, aeroelastic coupling primarily consists of torsional deformations. They neglect bending deformations, deformation velocities, and inertia terms. This paper validates the assumptions above for a General Aviation propeller and a lift propeller for urban air mobility or large cargo drones. Fully coupled reduced-order simulations determine the dynamic loads in the time domain. A quasi-steady blade element momentum approach transfers loads to one-dimensional finite beam elements. The simulation results are in relatively good agreement with the analytical method for the General Aviation propeller but show increasing errors for the slender lift propeller. The analytical approach is modified to consider the induced velocities. Still, inertia and velocity proportional terms play a significant role for the lift propeller due to increased elasticity. The assumption that only torsional deformations significantly impact the dynamic loads of propellers is not valid. Adequate determination of dynamic loads of such designs requires coupled aeroelastic simulations or advanced analytical procedures.}, 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. Boston, Massachusetts, USA. June 26-30, 2023}, booktitle = {Proceedings of the ASME Turbo Expo 2023: Turbomachinery Technical Conference and Exposition. Volume 1: Aircraft Engine. Boston, Massachusetts, USA. June 26-30, 2023}, 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} } @inproceedings{DachwaldWurm2009, author = {Dachwald, Bernd and Wurm, P.}, title = {Mission analysis for an advanced solar photon thruster}, series = {60th International Astronautical Congress 2009, IAC 2009}, volume = {Vol. 8}, booktitle = {60th International Astronautical Congress 2009, IAC 2009}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {978-161567908-9}, pages = {6838 -- 6851}, year = {2009}, abstract = {The so-called "compound solar sail", also known as "Solar Photon Thruster" (SPT), is a solar sail design concept, for which the two basic functions of the solar sail, namely light collection and thrust direction, are uncoupled. In this paper, we introduce a novel SPT concept, termed the Advanced Solar Photon Thruster (ASPT). This model does not suffer from the simplified assumptions that have been made for the analysis of compound solar sails in previous studies. We present the equations that describe the force, which acts on the ASPT. After a detailed design analysis, the performance of the ASPT with respect to the conventional flat solar sail (FSS) is investigated for three interplanetary mission scenarios: An Earth-Venus rendezvous, where the solar sail has to spiral towards the Sun, an Earth-Mars rendezvous, where the solar sail has to spiral away from the Sun, and an Earth-NEA rendezvous (to near-Earth asteroid 1996FG3), where a large orbital eccentricity change is required. The investigated solar sails have realistic near-term characteristic accelerations between 0.1 and 0.2mm/s2. Our results show that a SPT is not superior to the flat solar sail unless very idealistic assumptions are made.}, language = {en} } @inproceedings{GoettenFingerHavermannetal.2020, author = {G{\"o}tten, Falk and Finger, Felix and Havermann, Marc and Braun, Carsten and Marino, Matthew and Bil, Cees}, title = {Full Configuration Drag Estimation of Small-to-Medium Range UAVs and its Impact on Initial Sizing Optimization}, series = {Deutscher Luft- und Raumfahrtkongress - DLRK 2020}, booktitle = {Deutscher Luft- und Raumfahrtkongress - DLRK 2020}, year = {2020}, language = {en} } @inproceedings{GeibenGoettenHavermann2020, author = {Geiben, Benedikt and G{\"o}tten, Falk and Havermann, Marc}, title = {Aerodynamic analysis of a winged sub-orbital spaceplane}, series = {Deutscher Luft- und Raumfahrtkongress - DLRK 2020}, booktitle = {Deutscher Luft- und Raumfahrtkongress - DLRK 2020}, year = {2020}, language = {en} } @inproceedings{HippeFingerGoettenetal.2020, author = {Hippe, Jonas and Finger, Felix and G{\"o}tten, Falk and Braun, Carsten}, title = {Propulsion System Qualification of a 25 kg VTOL-UAV: Hover Performance of Single and Coaxial Rotors and Wind-Tunnel Experiments on Cruise Propellers}, series = {Deutscher Luft- und Raumfahrtkongress - DLRK 2020}, booktitle = {Deutscher Luft- und Raumfahrtkongress - DLRK 2020}, year = {2020}, language = {en} } @inproceedings{FingerGoettenBraunetal.2019, author = {Finger, Felix and G{\"o}tten, Falk and Braun, Carsten and Bil, C.}, title = {On Aircraft Design Under the Consideration of Hybrid-Electric Propulsion Systems}, series = {APISAT 2018: The Proceedings of the 2018 Asia-Pacific International Symposium on Aerospace Technology (APISAT 2018)}, booktitle = {APISAT 2018: The Proceedings of the 2018 Asia-Pacific International Symposium on Aerospace Technology (APISAT 2018)}, publisher = {Springer}, address = {Singapore}, isbn = {978-981-13-3305-7}, doi = {10.1007/978-981-13-3305-7_99}, pages = {1261 -- 1272}, year = {2019}, abstract = {A hybrid-electric propulsion system combines the advantages of fuel-based systems and battery powered systems and offers new design freedom. To take full advantage of this technology, aircraft designers must be aware of its key differences, compared to conventional, carbon-fuel based, propulsion systems. This paper gives an overview of the challenges and potential benefits associated with the design of aircraft that use hybrid-electric propulsion systems. It offers an introduction of the most popular hybrid-electric propulsion architectures and critically assess them against the conventional and fully electric propulsion configurations. The effects on operational aspects and design aspects are covered. Special consideration is given to the application of hybrid-electric propulsion technology to both unmanned and vertical take-off and landing aircraft. The authors conclude that electric propulsion technology has the potential to revolutionize aircraft design. However, new and innovative methods must be researched, to realize the full benefit of the technology.}, language = {en} } @inproceedings{GoettenFingerBraunetal.2019, author = {G{\"o}tten, Falk and Finger, Felix and Braun, Carsten and Havermann, Marc and Bil, C. and Gomez, F.}, title = {Empirical Correlations for Geometry Build-Up of Fixed Wing Unmanned Air Vehicles}, series = {APISAT 2018: The Proceedings of the 2018 Asia-Pacific International Symposium on Aerospace Technology (APISAT 2018)}, booktitle = {APISAT 2018: The Proceedings of the 2018 Asia-Pacific International Symposium on Aerospace Technology (APISAT 2018)}, publisher = {Springer}, address = {Singapore}, isbn = {978-981-13-3305-7}, doi = {10.1007/978-981-13-3305-7_109}, pages = {1365 -- 1381}, year = {2019}, abstract = {The results of a statistical investigation of 42 fixed-wing, small to medium sized (20 kg-1000 kg) reconnaissance unmanned air vehicles (UAVs) are presented. Regression analyses are used to identify correlations of the most relevant geometry dimensions with the UAV's maximum take-off mass. The findings allow an empirical based geometry-build up for a complete unmanned aircraft by referring to its take-off mass only. This provides a bridge between very early design stages (initial sizing) and the later determination of shapes and dimensions. The correlations might be integrated into a UAV sizing environment and allow designers to implement more sophisticated drag and weight estimation methods in this process. Additional information on correlation factors for a rough drag estimation methodology indicate how this technique can significantly enhance the accuracy of early design iterations.}, language = {en} } @inproceedings{ThomaFisherBraun2020, author = {Thoma, Andreas and Fisher, Alex and Braun, Carsten}, title = {Improving the px4 avoid algorithm by bio-inspired flight strategies}, series = {DLRK2020 - „Luft- und Raumfahrt - Verantwortung in allen Dimensionen"}, booktitle = {DLRK2020 - „Luft- und Raumfahrt - Verantwortung in allen Dimensionen"}, pages = {10 Seiten}, year = {2020}, language = {en} } @inproceedings{EnglhardWeberArent2021, author = {Englhard, Markus and Weber, Tobias and Arent, Jan-Christoph}, title = {Efficiency enhancement for CFRP-Prepregautoclave manufacturing by means of simulation-assisted loading optimization}, series = {Proceedings of SAMPE Europe Conference 2021}, booktitle = {Proceedings of SAMPE Europe Conference 2021}, pages = {8 Seiten}, year = {2021}, abstract = {A new method for improved autoclave loading within the restrictive framework of helicopter manufacturing is proposed. It is derived from experimental and numerical studies of the curing process and aims at optimizing tooling positions in the autoclave for fast and homogeneous heat-up. The mold positioning is based on two sets of information. The thermal properties of the molds, which can be determined via semi-empirical thermal simulation. The second information is a previously determined distribution of heat transfer coefficients inside the autoclave. Finally, an experimental proof of concept is performed to show a cycle time reduction of up to 31\% using the proposed methodology.}, language = {en} } @inproceedings{HauggKreyerKemperetal.2020, author = {Haugg, Albert Thomas and Kreyer, J{\"o}rg and Kemper, Hans and Hatesuer, Katerina and Esch, Thomas}, title = {Heat exchanger for ORC. adaptability and optimisation potentials}, series = {IIR International Rankine 2020 Conference}, booktitle = {IIR International Rankine 2020 Conference}, doi = {10.18462/iir.rankine.2020.1224}, pages = {10 Seiten}, year = {2020}, abstract = {The recovery of waste heat requires heat exchangers to extract it from a liquid or gaseous medium into another working medium, a refrigerant. In Organic Rankine Cycles (ORC) on Combustion Engines there are two major heat sources, the exhaust gas and the water/glycol fluid from the engine's cooling circuit. A heat exchanger design must be adapted to the different requirements and conditions resulting from the heat sources, fluids, system configurations, geometric restrictions, and etcetera. The Stacked Shell Cooler (SSC) is a new and very specific design of a plate heat exchanger, created by AKG, which allows with a maximum degree of freedom the optimization of heat exchange rate and the reduction of the related pressure drop. This optimization in heat exchanger design for ORC systems is even more important, because it reduces the energy consumption of the system and therefore maximizes the increase in overall efficiency of the engine.}, language = {en} } @inproceedings{HoevelerJanser2016, author = {Hoeveler, Bastian and Janser, Frank}, title = {The aerodynamically optimized design of a fan-in-wing duct}, series = {Applied Aerodynamics Research Conference 2016, Bristol, GB, Jul 19-21, 2016}, booktitle = {Applied Aerodynamics Research Conference 2016, Bristol, GB, Jul 19-21, 2016}, isbn = {1-85768-371-4}, pages = {1 -- 10}, year = {2016}, language = {en} } @inproceedings{GrundmannBauerBorchersetal.2019, author = {Grundmann, Jan Thimo and Bauer, Wlademar and Borchers, Kai and Dumont, Etienne and Grimm, Christian D. and Ho, Tra-Mi and Jahnke, Rico and Koch, Aaron D. and Lange, Caroline and Maiwald, Volker and Meß, Jan-Gerd and Mikulz, Eugen and Quantius, Dominik and Reershemius, Siebo and Renger, Thomas and Sasaki, Kaname and Seefeldt, Patric and Spietz, Peter and Spr{\"o}witz, Tom and Sznajder, Maciej and Toth, Norbert and Ceriotti, Matteo and McInnes, Colin and Peloni, Alessandro and Biele, Jens and Krause, Christian and Dachwald, Bernd and Hercik, David and Lichtenheldt, Roy and Wolff, Friederike and Koncz, Alexander and Pelivan, Ivanka and Schmitz, Nicole and Boden, Ralf and Riemann, Johannes and Seboldt, Wolfgang and Wejmo, Elisabet and Ziach, Christian and Mikschl, Tobias and Montenegro, Sergio and Ruffer, Michael and Cordero, Federico and Tardivel, Simon}, title = {Solar sails for planetary defense \& high-energy missions}, series = {IEEE Aerospace Conference Proceedings}, booktitle = {IEEE Aerospace Conference Proceedings}, doi = {10.1109/AERO.2019.8741900}, pages = {1 -- 21}, year = {2019}, abstract = {20 years after the successful ground deployment test of a (20 m) 2 solar sail at DLR Cologne, and in the light of the upcoming U.S. NEAscout mission, we provide an overview of the progress made since in our mission and hardware design studies as well as the hardware built in the course of our solar sail technology development. We outline the most likely and most efficient routes to develop solar sails for useful missions in science and applications, based on our developed `now-term' and near-term hardware as well as the many practical and managerial lessons learned from the DLR-ESTEC Gossamer Roadmap. Mission types directly applicable to planetary defense include single and Multiple NEA Rendezvous ((M)NR) for precursor, monitoring and follow-up scenarios as well as sail-propelled head-on retrograde kinetic impactors (RKI) for mitigation. Other mission types such as the Displaced L1 (DL1) space weather advance warning and monitoring or Solar Polar Orbiter (SPO) types demonstrate the capability of near-term solar sails to achieve asteroid rendezvous in any kind of orbit, from Earth-coorbital to extremely inclined and even retrograde orbits. Some of these mission types such as SPO, (M)NR and RKI include separable payloads. For one-way access to the asteroid surface, nanolanders like MASCOT are an ideal match for solar sails in micro-spacecraft format, i.e. in launch configurations compatible with ESPA and ASAP secondary payload platforms. Larger landers similar to the JAXA-DLR study of a Jupiter Trojan asteroid lander for the OKEANOS mission can shuttle from the sail to the asteroids visited and enable multiple NEA sample-return missions. The high impact velocities and re-try capability achieved by the RKI mission type on a final orbit identical to the target asteroid's but retrograde to its motion enables small spacecraft size impactors to carry sufficient kinetic energy for deflection.}, language = {en} } @inproceedings{FingerdeVriesVosetal.2020, author = {Finger, Felix and de Vries, Reynard and Vos, Roelof and Braun, Carsten and Bil, Cees}, title = {A comparison of hybrid-electric aircraft sizing methods}, series = {AIAA Scitech 2020 Forum}, booktitle = {AIAA Scitech 2020 Forum}, doi = {10.2514/6.2020-1006}, pages = {31 Seiten}, year = {2020}, language = {en} } @inproceedings{KreyerMuellerEsch2020, author = {Kreyer, J{\"o}rg and M{\"u}ller, Marvin and Esch, Thomas}, title = {A Map-Based Model for the Determination of Fuel Consumption for Internal Combustion Engines as a Function of Flight Altitude}, series = {Deutscher Luft- und Raumfahrtkongress 2019, „Luft- und Raumfahrt - technologische Br{\"u}cke in die Zukunft", Darmstadt, 30. September bis 2. Oktober 2019}, booktitle = {Deutscher Luft- und Raumfahrtkongress 2019, „Luft- und Raumfahrt - technologische Br{\"u}cke in die Zukunft", Darmstadt, 30. September bis 2. Oktober 2019}, publisher = {Deutsche Gesellschaft f{\"u}r Luft- und Raumfahrt - Lilienthal-Oberth e.V}, address = {Bonn}, doi = {10.25967/490162}, pages = {13 Seiten}, year = {2020}, language = {en} } @inproceedings{FingerGoettenBraunetal.2019, author = {Finger, Felix and G{\"o}tten, Falk and Braun, Carsten and Bil, Cees}, title = {Cost Estimation Methods for Hybrid-Electric General Aviation Aircraft}, series = {Asia Pacific International Symposium on Aerospace Technology. APISAT 2019}, booktitle = {Asia Pacific International Symposium on Aerospace Technology. APISAT 2019}, pages = {1 -- 13}, year = {2019}, language = {en} } @inproceedings{FingerBraunBil2020, author = {Finger, Felix and Braun, Carsten and Bil, Cees}, title = {Comparative assessment of parallel-hybrid-electric propulsion systems for four different aircraft}, series = {AIAA SciTech Forum 2020, 06.01.2020 - 10.01.2020, Orlando}, booktitle = {AIAA SciTech Forum 2020, 06.01.2020 - 10.01.2020, Orlando}, doi = {10.2514/6.2020-1502}, pages = {15 Seiten}, year = {2020}, language = {en} } @inproceedings{GoettenFingerMarinoetal.2019, author = {G{\"o}tten, Falk and Finger, Felix and Marino, Matthew and Bil, Cees and Havermann, Marc and Braun, Carsten}, title = {A review of guidelines and best practices for subsonic aerodynamic simulations using RANS CFD}, series = {Asia-Pacific International Symposium on Aerospace Technology (APISAT), At Gold Coast, Australia, 04. - 06. Dezember 2019}, booktitle = {Asia-Pacific International Symposium on Aerospace Technology (APISAT), At Gold Coast, Australia, 04. - 06. Dezember 2019}, isbn = {978-1-925627-40-4}, pages = {19 Seiten}, year = {2019}, language = {de} } @inproceedings{FingerKhalsaKreyeretal.2019, author = {Finger, Felix and Khalsa, R. and Kreyer, J{\"o}rg and Mayntz, Joscha and Braun, Carsten and Dahmann, Peter and Esch, Thomas and Kemper, Hans and Schmitz, O. and Bragard, Michael}, title = {An approach to propulsion system modelling for the conceptual design of hybrid-electric general aviation aircraft}, series = {Deutscher Luft- und Raumfahrtkongress 2019, 30.9.-2.10.2019, Darmstadt}, booktitle = {Deutscher Luft- und Raumfahrtkongress 2019, 30.9.-2.10.2019, Darmstadt}, pages = {15 Seiten}, year = {2019}, abstract = {In this paper, an approach to propulsion system modelling for hybrid-electric general aviation aircraft is presented. Because the focus is on general aviation aircraft, only combinations of electric motors and reciprocating combustion engines are explored. Gas turbine hybrids will not be considered. The level of the component's models is appropriate for the conceptual design stage. They are simple and adaptable, so that a wide range of designs with morphologically different propulsive system architectures can be quickly compared. Modelling strategies for both mass and efficiency of each part of the propulsion system (engine, motor, battery and propeller) will be presented.}, language = {en} } @inproceedings{QuitterMarinoBauschat2019, author = {Quitter, Julius and Marino, Matthew and Bauschat, J.-Michael}, title = {Highly Non-Planar Aircraft Configurations: Estimation of Flight Mechanical Derivatives Using Low-Order Methods}, series = {Deutscher Luft- und Raumfahrtkongress 2019, DLRK 2019. Darmstadt, Germany}, booktitle = {Deutscher Luft- und Raumfahrtkongress 2019, DLRK 2019. Darmstadt, Germany}, pages = {10 Seiten}, year = {2019}, language = {en} } @inproceedings{FunkeBeckmannAbanteriba2017, author = {Funke, Harald and Beckmann, Nils and Abanteriba, Sylvester}, title = {A comparison of complex chemistry mechanisms for hydrogen methane blends based on the Sandia / Sydney Bluff-Body Flame HM1}, series = {Proceedings of the Eleventh Asia-Pacific Conference on Combustion (ASPACC 2017), New South Wales, Australia, 10-14 December 2017}, booktitle = {Proceedings of the Eleventh Asia-Pacific Conference on Combustion (ASPACC 2017), New South Wales, Australia, 10-14 December 2017}, isbn = {978-1-5108-5646-2}, pages = {262 -- 265}, year = {2017}, language = {en} } @inproceedings{FunkeBeckmannAbanteriba2019, author = {Funke, Harald and Beckmann, Nils and Abanteriba, Sylvester}, title = {Development and Testing of a FuelFlex Dry-Low-NOx Micromix Combustor for Industrial Gas Turbine Applications With Variable Hydrogen Methane Mixtures}, series = {ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition. June 17-21, 2019 Phoenix, Arizona, USA. Volume 4A: Combustion, Fuels, and Emissions}, booktitle = {ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition. June 17-21, 2019 Phoenix, Arizona, USA. Volume 4A: Combustion, Fuels, and Emissions}, isbn = {978-0-7918-5861-5}, doi = {10.1115/GT2019-90095}, pages = {11 Seiten}, year = {2019}, language = {en} } @inproceedings{HorikawaOkadaUtoetal.2019, author = {Horikawa, Atsushi and Okada, Kunio and Uto, Takahiro and Uchiyama, Yuta and Wirsum, Manfred and Funke, Harald and Kusterer, Karsten}, title = {Application of Low NOx Micro-mix Hydrogen Combustion to 2MW Class Industrial Gas Turbine Combustor}, series = {Proceedings of International Gas Turbine Congress 2019 Tokyo, November 17-22, 2019, Tokyo, Japan}, booktitle = {Proceedings of International Gas Turbine Congress 2019 Tokyo, November 17-22, 2019, Tokyo, Japan}, isbn = {978-4-89111-010-9}, pages = {1 -- 6}, year = {2019}, language = {en} } @inproceedings{FunkeBeckmann2019, author = {Funke, Harald and Beckmann, Nils}, title = {Flexible Fuel Operation of a Dry-Low-Nox Micromix Combustor with Variable Hydrogen Methane Mixtures}, series = {Proceedings of International Gas Turbine Congress 2019 Tokyo, November 17-22, 2019, Tokyo, Japan}, booktitle = {Proceedings of International Gas Turbine Congress 2019 Tokyo, November 17-22, 2019, Tokyo, Japan}, isbn = {978-4-89111-010-9}, year = {2019}, language = {en} } @inproceedings{StrieganStruthDickhoffetal.2019, author = {Striegan, Constantin J. D. and Struth, Benjamin and Dickhoff, Jens and Kusterer, Karsten and Funke, Harald and Bohn, Dieter}, title = {Numerical Simulations of the Micromix DLN Hydrogen Combustion Technology with LES and Comparison to Results of RANS and Experimental Data}, series = {Proceedings of International Gas Turbine Congress 2019 Tokyo, November 17-22, 2019, Tokyo, Japan.}, booktitle = {Proceedings of International Gas Turbine Congress 2019 Tokyo, November 17-22, 2019, Tokyo, Japan.}, isbn = {978-4-89111-010-9}, pages = {1 -- 9}, year = {2019}, language = {en} } @inproceedings{OttenSchmidtWeber2016, author = {Otten, D. and Schmidt, M. and Weber, Tobias}, title = {Advances in Determination of Material Parameters for Functional Simulations Based on Process Simulations}, series = {SAMPE Europe Conference 16 Liege}, booktitle = {SAMPE Europe Conference 16 Liege}, isbn = {978-1-5108-3800-0}, pages = {570 -- 577}, year = {2016}, language = {en} } @inproceedings{WeberTellisDuhovic2016, author = {Weber, Tobias and Tellis, Jane J. and Duhovic, Miro}, title = {Characterization of tool-part-interaction an interlaminar friction for manufacturing process simulation}, series = {ECCM 17, 17th European Conference on Composite Materials, M{\"u}nchen, DE, Jun 26-30, 2016}, booktitle = {ECCM 17, 17th European Conference on Composite Materials, M{\"u}nchen, DE, Jun 26-30, 2016}, isbn = {978-3-00-053387-7}, pages = {1 -- 7}, year = {2016}, language = {en} } @inproceedings{AyedStrieganKustereretal.2017, author = {Ayed, Anis Haj and Striegan, Constantin J. D. and Kusterer, Karsten and Funke, Harald and Kazari, M. and Horikawa, Atsushi and Okada, Kunio}, title = {Automated design space exploration of the hydrogen fueled "Micromix" combustor technology}, pages = {1 -- 8}, year = {2017}, abstract = {Combined with the use of renewable energy sources for its production, Hydrogen represents a possible alternative gas turbine fuel for future low emission power generation. Due to its different physical properties compared to other fuels such as natural gas, well established gas turbine combustion systems cannot be directly applied for Dry Low NOx (DLN) Hydrogen combustion. This makes the development of new combustion technologies an essential and challenging task for the future of hydrogen fueled gas turbines. The newly developed and successfully tested "DLN Micromix" combustion technology offers a great potential to burn hydrogen in gas turbines at very low NOx emissions. Aiming to further develop an existing burner design in terms of increased energy density, a redesign is required in order to stabilise the flames at higher mass flows and to maintain low emission levels. For this purpose, a systematic design exploration has been carried out with the support of CFD and optimisation tools to identify the interactions of geometrical and design parameters on the combustor performance. Aerodynamic effects as well as flame and emission formation are observed and understood time- and cost-efficiently. Correlations between single geometric values, the pressure drop of the burner and NOx production have been identified as a result. This numeric methodology helps to reduce the effort of manufacturing and testing to few designs for single validation campaigns, in order to confirm the flame stability and NOx emissions in a wider operating condition field.}, language = {en} } @inproceedings{FunkeBeckmannKeinzetal.2021, author = {Funke, Harald and Beckmann, Nils and Keinz, Jan and Horikawa, Atsushi}, title = {30 years of dry low NOx micromix combustor research for hydrogen-rich fuels: an overview of past and present activities}, series = {Proceedings of the ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition, September 21-25, 2020, Virtual, Online. Vol.: 4B: Combustion, Fuels, and Emissions}, booktitle = {Proceedings of the ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition, September 21-25, 2020, Virtual, Online. Vol.: 4B: Combustion, Fuels, and Emissions}, publisher = {American Society of Mechanical Engineers (ASME)}, isbn = {978-0-7918-8413-3}, doi = {10.1115/GT2020-16328}, pages = {14 Seiten}, year = {2021}, language = {en} } @inproceedings{BergmannGraebenerWildetal.2019, author = {Bergmann, Kevin and Gr{\"a}bener, Josefine and Wild, Dominik and Ulfers, H. and Czupalla, Markus}, title = {Study on thermal stabilization of a GEO-stationary telescope baffling system by integral application of phase change material}, series = {International Conference on Environmental Systems}, booktitle = {International Conference on Environmental Systems}, pages = {1 -- 14}, year = {2019}, abstract = {The utilization of phase change material (PCM) for latent heat storage and thermal control of spacecraft has been demonstrated in the past in few missions only. One limiting factor was the fact that all concepts developed so far envisioned the PCM to be applied as an additional capacitor, encapsulated in its own housing, leading to mass, efficiency and accommodation challenges. Recently, the application of PCM within the scan cavity of a GEOS type satellite has been suggested, in order to tackle thermal issues due to direct sun intrusion (Choi, M., 2014). However, the application of PCM in such complex mechanical structures is extremely challenging. A new concept to tackle this issue is currently under development at the FH Aachen University of Applied Sciences. The concept "Infused Thermal Solutions (ITS)" is based on the idea to 3D print metallic structures in their regular functional shape, but double walled with internal lattice support structures, allowing the infusion of a PCM layer directly into the voids and eliminating the need for additional parts and interfaces. Together with OHB System, FH Aachen theoretically studied the application of this technology to the Meteosat Third Generation (MTG) Infra-Red Sounder (IRS) instrument. The study focuses on the scan cavity and entrance baffling assembly (EBA) of the IRS. It consists of thermal analyses, 3D-redesign and bread boarding of a scaled and PCM infused EBA version. In the thermal design of the alternative EBA, PCM was applied directly into the EBA, simulating the worst hot case sun intrusion of the mission. By applying 4kg of PCM (to a 60kg baffle) the EBA temperature excursions during sun intrusion were limited from 140K to 30K, leading to a significant thermo-opto-elastic performance gain. This paper introduces the ITS concept development status.}, language = {en} } @inproceedings{AdamsLosekammCzupalla2020, author = {Adams, Moritz and Losekamm, Martin J. and Czupalla, Markus}, title = {Development of the Thermal Control System for the RadMap Telescope Experiment on the International Space Station}, series = {International Conference on Environmental Systems}, booktitle = {International Conference on Environmental Systems}, pages = {1 -- 10}, year = {2020}, language = {en} } @inproceedings{ThomaFisherBertrandetal.2020, author = {Thoma, Andreas and Fisher, Alex and Bertrand, Olivier and Braun, Carsten}, title = {Evaluation of possible flight strategies for close object evasion from bumblebee experiments}, series = {Living Machines 2020: Biomimetic and Biohybrid Systems}, booktitle = {Living Machines 2020: Biomimetic and Biohybrid Systems}, editor = {Vouloutsi, Vasiliki and Mura, Anna and Tauber, Falk and Speck, Thomas and Prescott, Tony J. and Verschure, Paul F. M. J.}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-64312-6}, doi = {10.1007/978-3-030-64313-3_34}, pages = {354 -- 365}, year = {2020}, language = {en} } @inproceedings{OhndorfDachwaldSeboldtetal.2011, author = {Ohndorf, Andreas and Dachwald, Bernd and Seboldt, Wolfgang and Schartner, Karl-Heinz}, title = {Flight times to the heliopause using a combination of solar and radioisotope electric propulsion}, series = {32nd International Electric Propulsion Conference}, booktitle = {32nd International Electric Propulsion Conference}, pages = {1 -- 12}, year = {2011}, abstract = {We investigate the interplanetary flight of a low-thrust space probe to the heliopause,located at a distance of about 200 AU from the Sun. Our goal was to reach this distance within the 25 years postulated by ESA for such a mission (which is less ambitious than the 15-year goal set by NASA). Contrary to solar sail concepts and combinations of allistic and electrically propelled flight legs, we have investigated whether the set flight time limit could also be kept with a combination of solar-electric propulsion and a second, RTG-powered upper stage. The used ion engine type was the RIT-22 for the first stage and the RIT-10 for the second stage. Trajectory optimization was carried out with the low-thrust optimization program InTrance, which implements the method of Evolutionary Neurocontrol,using Artificial Neural Networks for spacecraft steering and Evolutionary Algorithms to optimize the Neural Networks' parameter set. Based on a parameter space study, in which the number of thrust units, the unit's specific impulse, and the relative size of the solar power generator were varied, we have chosen one configuration as reference. The transfer time of this reference configuration was 29.6 years and the fastest one, which is technically more challenging, still required 28.3 years. As all flight times of this parameter study were longer than 25 years, we further shortened the transfer time by applying a launcher-provided hyperbolic excess energy up to 49 km2/s2. The resulting minimal flight time for the reference configuration was then 27.8 years. The following, more precise optimization to a launch with the European Ariane 5 ECA rocket reduced the transfer time to 27.5 years. This is the fastest mission design of our study that is flexible enough to allow a launch every year. The inclusion of a fly-by at Jupiter finally resulted in a flight time of 23.8 years,which is below the set transfer-time limit. However, compared to the 27.5-year transfer,this mission design has a significantly reduced launch window and mission flexibility if the escape direction is restricted to the heliosphere's "nose".}, language = {en} } @inproceedings{BorggraefeDachwald2010, author = {Borggr{\"a}fe, Andreas and Dachwald, Bernd}, title = {Mission performance evaluation for solar sails using a refined SRP force model with variable optical coefficients}, series = {2nd International Symposium on Solar Sailing}, booktitle = {2nd International Symposium on Solar Sailing}, pages = {1 -- 6}, year = {2010}, abstract = {Solar sails provide ignificant advantages over other low-thrust propulsion systems because they produce thrust by the momentum exchange from solar radiation pressure (SRP) and thus do not consume any propellant.The force exerted on a very thin sail foil basically depends on the light incidence angle. Several analytical SRP force models that describe the SRP force acting on the sail have been established since the 1970s. All the widely used models use constant optical force coefficients of the reflecting sail material. In 2006,MENGALI et al. proposed a refined SRP force model that takes into account the dependancy of the force coefficients on the light incident angle,the sail's distance from the sun (and thus the sail emperature) and the surface roughness of the sail material [1]. In this paper, the refined SRP force model is compared to the previous ones in order to identify the potential impact of the new model on the predicted capabilities of solar sails in performing low-cost interplanetary space missions. All force models have been implemented within InTrance, a global low-thrust trajectory optimization software utilizing evolutionary neurocontrol [2]. Two interplanetary rendezvous missions, to Mercury and the near-Earth asteroid 1996FG3, are investigated. Two solar sail performances in terms of characteristic acceleration are examined for both scenarios, 0.2 mm/s2 and 0.5 mm/s2, termed "low" and "medium" sail performance. In case of the refined SRP model, three different values of surface roughness are chosen, h = 0 nm, 10 nm and 25 nm. The results show that the refined SRP force model yields shorter transfer times than the standard model.}, language = {en} } @inproceedings{KronigerHorikawaFunkeetal.2021, author = {Kroniger, Daniel and Horikawa, Atsushi and Funke, Harald and Pf{\"a}ffle, Franziska and Kishimoto, Tsuyoshi and Okada, Koichi}, title = {Experimental and numerical investigation on the effect of pressure on micromix hydrogen combustion}, series = {ASME Turbo Expo 2021: Turbomachinery Technical Conference and Exposition // Volume 3A: Combustion, Fuels, and Emissions}, booktitle = {ASME Turbo Expo 2021: Turbomachinery Technical Conference and Exposition // Volume 3A: Combustion, Fuels, and Emissions}, doi = {10.1115/GT2021-58926}, pages = {11 Seiten}, year = {2021}, abstract = {The micromix (MMX) combustion concept is a DLN gas turbine combustion technology designed for high hydrogen content fuels. Multiple non-premixed miniaturized flames based on jet in cross-flow (JICF) are inherently safe against flashback and ensure a stable operation in various operative conditions. The objective of this paper is to investigate the influence of pressure on the micromix flame with focus on the flame initiation point and the NOx emissions. A numerical model based on a steady RANS approach and the Complex Chemistry model with relevant reactions of the GRI 3.0 mechanism is used to predict the reactive flow and NOx emissions at various pressure conditions. Regarding the turbulence-chemical interaction, the Laminar Flame Concept (LFC) and the Eddy Dissipation Concept (EDC) are compared. The numerical results are validated against experimental results that have been acquired at a high pressure test facility for industrial can-type gas turbine combustors with regard to flame initiation and NOx emissions. The numerical approach is adequate to predict the flame initiation point and NOx emission trends. Interestingly, the flame shifts its initiation point during the pressure increase in upstream direction, whereby the flame attachment shifts from anchoring behind a downstream located bluff body towards anchoring directly at the hydrogen jet. The LFC predicts this change and the NOx emissions more accurately than the EDC. The resulting NOx correlation regarding the pressure is similar to a non-premixed type combustion configuration.}, language = {en} } @inproceedings{DachwaldKahleWie2007, author = {Dachwald, Bernd and Kahle, Ralph and Wie, Bong}, title = {Head-on impact deflection of NEAs: a case study for 99942 Apophis}, series = {Planetary Defense Conference 2007}, booktitle = {Planetary Defense Conference 2007}, pages = {1 -- 12}, year = {2007}, abstract = {Near-Earth asteroid (NEA) 99942 Apophis provides a typical example for the evolution of asteroid orbits that lead to Earth-impacts after a close Earth-encounter that results in a resonant return. Apophis will have a close Earth-encounter in 2029 with potential very close subsequent Earth-encounters (or even an impact) in 2036 or later, depending on whether it passes through one of several less than 1 km-sized gravitational keyholes during its 2029-encounter. A pre-2029 kinetic impact is a very favorable option to nudge the asteroid out of a keyhole. The highest impact velocity and thus deflection can be achieved from a trajectory that is retrograde to Apophis orbit. With a chemical or electric propulsion system, however, many gravity assists and thus a long time is required to achieve this. We show in this paper that the solar sail might be the better propulsion system for such a mission: a solar sail Kinetic Energy Impactor (KEI) spacecraft could impact Apophis from a retrograde trajectory with a very high relative velocity (75-80 km/s) during one of its perihelion passages. The spacecraft consists of a 160 m × 160 m, 168 kg solar sail assembly and a 150 kg impactor. Although conventional spacecraft can also achieve the required minimum deflection of 1 km for this approx. 320 m-sized object from a prograde trajectory, our solar sail KEI concept also allows the deflection of larger objects. For a launch in 2020, we also show that, even after Apophis has flown through one of the gravitational keyholes in 2029, the solar sail KEI concept is still feasible to prevent Apophis from impacting the Earth, but many KEIs would be required for consecutive impacts to increase the total Earth-miss distance to a safe value}, language = {en} } @inproceedings{GrundmannBodenCeriottietal.2017, author = {Grundmann, Jan Thimo and Boden, Ralf and Ceriotti, Matteo and Dachwald, Bernd and Dumont, Etienne and Grimm, Christian D. and Lange, Caroline and Lichtenheldt, Roy and Pelivan, Ivanka and Peloni, Alessandro and Riemann, Johannes and Spr{\"o}witz, Tom and Tardivel, Simon}, title = {Soil to sail-asteroid landers on near-term sailcraft as an evolution of the GOSSAMER small spacecraft solar sail concept for in-situ characterization}, series = {5th IAA Planetary Defense Conference}, booktitle = {5th IAA Planetary Defense Conference}, pages = {30 Seiten}, year = {2017}, language = {en} } @inproceedings{SeboldtDachwald2003, author = {Seboldt, Wolfgang and Dachwald, Bernd}, title = {Solar sails for near-term advanced scientific deep space missions}, series = {Proceedings of the 8th International Workshop on Combustion and Propulsion}, booktitle = {Proceedings of the 8th International Workshop on Combustion and Propulsion}, pages = {14 Seiten}, year = {2003}, abstract = {Solar sails are propelled in space by reflecting solar photons off large mirroring surfaces, thereby transforming the momentum of the photons into a propulsive force. This innovative concept for low-thrust space propulsion works without any propellant and thus provides a wide range of opportunities for highenergy low-cost missions. Offering an efficient way of propulsion, solar sailcraft could close a gap in transportation options for highly demanding exploration missions within our solar system and even beyond. On December 17th, 1999, a significant step was made towards the realization of this technology: a lightweight solar sail structure with an area of 20 m × 20 m was successfully deployed on ground in a large facility at the German Aerospace Center (DLR) at Cologne. The deployment from a package of 60 cm × 60 cm × 65 cm with a total mass of less than 35 kg was achieved using four extremely light-weight carbon fiber reinforced plastics (CFRP) booms with a specific mass of 100 g/m. The paper briefly reviews the basic principles of solar sails as well as the technical concept and its realization in the ground demonstration experiment, performed in close cooperation between DLR and ESA. Next possible steps are outlined. They could comprise the in-orbit demonstration of the sail deployment on the upper stage of a low-cost rocket and the verification of the propulsion concept by an autonomous and free flying solar sail in the frame of a scientific mission. It is expected that the present design could be extended to sail sizes of about (40 m)2 up to even (70 m)2 without significant mass penalty. With these areas, the maximum achievable thrust at 1 AU would range between 10 and 40 mN - comparable to some electric thrusters. Such prototype sails with a mass between 50 and 150 kg plus a micro-spacecraft of 50 to 250 kg would have a maximum acceleration in the order of 0.1 mm/s2 at 1 AU, corresponding to a maximum ∆V-capability of about 3 km/s per year. Two near/medium-term mission examples to a near-Earth asteroid (NEA) will be discussed: a rendezvous mission and a sample return mission.}, language = {en} } @inproceedings{DachwaldSeboldtHaeusler2002, author = {Dachwald, Bernd and Seboldt, Wolfgang and H{\"a}usler, Bernd}, title = {Performance requirements for near-term interplanetary solar sailcraft missions}, series = {6th International AAAF Symposium on Space Propulsion: Propulsion for Space Transportation of the XXIst Century}, booktitle = {6th International AAAF Symposium on Space Propulsion: Propulsion for Space Transportation of the XXIst Century}, pages = {9 Seiten}, year = {2002}, abstract = {Solar sailcraft provide a wide range of opportunities for high-energy low-cost missions. To date, most mission studies require a rather demanding performance that will not be realized by solar sailcraft of the first generation. However, even with solar sailcraft of moderate performance, scientifically relevant missions are feasible. This is demonstrated with a Near Earth Asteroid sample return mission and various planetary rendezvous missions.}, language = {en} } @inproceedings{SchartnerLoebDachwaldetal.2009, author = {Schartner, Karl-Heinz and Loeb, H. W. and Dachwald, Bernd and Ohndorf, Andreas}, title = {Perspectives of electric propulsion for outer planetary and deep space missions}, series = {European Planetary Science Congress 2009}, booktitle = {European Planetary Science Congress 2009}, pages = {416 -- 416}, year = {2009}, abstract = {Solar-electric propulsion (SEP) is superior with respect to payload capacity, flight time and flexible launch window to the conventional interplanetary transfer method using chemical propulsion combined with gravity assists. This fact results from the large exhaust velocities of electric low-thrust propulsion and is favourable also for missions to the giant planets, Kuiper-belt objects and even for a heliopause probe (IHP) as shown in three studies by the authors funded by DLR. They dealt with a lander for Europa and a sample return mission from a mainbelt asteroid [1], with the TANDEM mission [2]; the third recent one investigates electric propulsion for the transfer to the edge of the solar system. All studies are based on triple-junction solar arrays, on rf-ion thrusters of the qualified RIT-22 type and they use the intelligent trajectory optimization program InTrance [3].}, language = {en} } @inproceedings{SpurmannOhndorfDachwaldetal.2009, author = {Spurmann, J{\"o}rn and Ohndorf, Andreas and Dachwald, Bernd and Seboldt, Wolfgang and L{\"o}b, Horst and Schartner, Karl-Heinz}, title = {Interplanetary trajectory optimization for a sep mission to Saturn}, series = {60th International Astronautical Congress 2009}, booktitle = {60th International Astronautical Congress 2009}, isbn = {9781615679089}, pages = {5234 -- 5248}, year = {2009}, abstract = {The recently proposed NASA and ESA missions to Saturn and Jupiter pose difficult tasks to mission designers because chemical propulsion scenarios are not capable of transferring heavy spacecraft into the outer solar system without the use of gravity assists. Thus our developed mission scenario based on the joint NASA/ESA Titan Saturn System Mission baselines solar electric propulsion to improve mission flexibility and transfer time. For the calculation of near-globally optimal low-thrust trajectories, we have used a method called Evolutionary Neurocontrol, which is implemented in the low-thrust trajectory optimization software InTrance. The studied solar electric propulsion scenario covers trajectory optimization of the interplanetary transfer including variations of the spacecraft's thrust level, the thrust unit's specific impulse and the solar power generator power level. Additionally developed software extensions enabled trajectory optimization with launcher-provided hyperbolic excess energy, a complex solar power generator model and a variable specific impulse ion engine model. For the investigated mission scenario, Evolutionary Neurocontrol yields good optimization results, which also hold valid for the more elaborate spacecraft models. Compared to Cassini/Huygens, the best found solutions have faster transfer times and a higher mission flexibility in general.}, language = {en} } @inproceedings{LoebSchartnerDachwaldetal.2007, author = {Loeb, Horst Wolfgang and Schartner, Karl-Heinz and Dachwald, Bernd and Seboldt, Wolfgang}, title = {SEP-Sample return from a main belt asteroid}, series = {30th International Electric Propulsion Conference}, booktitle = {30th International Electric Propulsion Conference}, pages = {1 -- 11}, year = {2007}, abstract = {By DLR-contact, sample return missions to the large main-belt asteroid "19, Fortuna" have been studied. The mission scenario has been based on three ion thrusters of the RIT-22 model, which is presently under space qualification, and on solar arrays equipped with triple-junction GaAs solar cells. After having designed the spacecraft, the orbit-to-orbit trajectories for both, a one-way SEP mission with a chemical sample return and an all-SEP return mission, have been optimized using a combination of artificial neural networks with evolutionary algorithms. Additionally, body-to-body trajectories have been investigated within a launch period between 2012 and 2015. For orbit-to-orbit calculation, the launch masses of the hybrid mission and of the all-SEP mission resulted in 2.05 tons and 1.56 tons, respectively, including a scientific payload of 246 kg. For the related transfer durations 4.14 yrs and 4.62 yrs were obtained. Finally, a comparison between the mission scenarios based on SEP and on NEP have been carried out favouring clearly SEP.}, language = {en} } @inproceedings{DachwaldMengaliQuartaetal.2007, author = {Dachwald, Bernd and Mengali, Giovanni and Quarta, Alessandro A and Macdonald, Malcolm and McInnes, Colin R}, title = {Optical solar sail degradation modelling}, series = {1st International Symposium on Solar Sailing}, booktitle = {1st International Symposium on Solar Sailing}, pages = {1 -- 27}, year = {2007}, abstract = {We propose a simple parametric OSSD 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.}, language = {en} } @inproceedings{SchoutetensDachwaldHeiligers2021, author = {Schoutetens, Frederic and Dachwald, Bernd and Heiligers, Jeannette}, title = {Optimisation of photon-sail trajectories in the alpha-centauri system using evolutionary neurocontrol}, series = {8th ICATT (International Conference on Astrodynamics Tools and Techniques) 23 - 25 June 2021, Virtual}, booktitle = {8th ICATT (International Conference on Astrodynamics Tools and Techniques) 23 - 25 June 2021, Virtual}, pages = {1 -- 15}, year = {2021}, abstract = {With the increased interest for interstellar exploration after the discovery of exoplanets and the proposal by Breakthrough Starshot, this paper investigates the optimisation of photon-sail trajectories in Alpha Centauri. The prime objective is to find the optimal steering strategy for a photonic sail to get captured around one of the stars after a minimum-time transfer from Earth. By extending the idea of the Breakthrough Starshot project with a deceleration phase upon arrival, the mission's scientific yield will be increased. As a secondary objective, transfer trajectories between the stars and orbit-raising manoeuvres to explore the habitable zones of the stars are investigated. All trajectories are optimised for minimum time of flight using the trajectory optimisation software InTrance. Depending on the sail technology, interstellar travel times of 77.6-18,790 years can be achieved, which presents an average improvement of 30\% with respect to previous work. Still, significant technological development is required to reach and be captured in the Alpha-Centauri system in less than a century. Therefore, a fly-through mission arguably remains the only option for a first exploratory mission to Alpha Centauri, but the enticing results obtained in this work provide perspective for future long-residence missions to our closest neighbouring star system.}, language = {en} } @inproceedings{SeefeldtBauerDachwaldetal.2015, author = {Seefeldt, Patric and Bauer, Waldemar and Dachwald, Bernd and Grundmann, Jan Thimo and Straubel, Marco and Sznajder, Maciej and T{\´o}th, Norbert and Zander, Martin E.}, title = {Large lightweight deployable structures for planetary defence: solar sail propulsion, solar concentrator payloads, large-scale photovoltaic power}, series = {4th IAA Planetary Defense Conference - PDC 2015, 13-17 April 2015, Frascati, Roma, Italy}, booktitle = {4th IAA Planetary Defense Conference - PDC 2015, 13-17 April 2015, Frascati, Roma, Italy}, pages = {24}, year = {2015}, language = {en} } @inproceedings{Dachwald2017, author = {Dachwald, Bernd}, title = {Radiation pressure force model for an ideal laser-enhanced solar sail}, series = {4th International Symposium on Solar Sailing}, booktitle = {4th International Symposium on Solar Sailing}, pages = {1 -- 5}, year = {2017}, abstract = {The concept of a laser-enhanced solar sail is introduced and the radiation pressure force model for an ideal laser-enhanced solar sail is derived. A laser-enhanced solar sail is a "traditional" solar sail that is, however, not solely propelled by solar radiation, but additionally by a laser beam that illuminates the sail. The additional laser radiation pressure increases the sail's propulsive force and can give, depending on the location of the laser source, more control authority over the direction of the solar sail's propulsive force vector. This way, laser-enhanced solar sails may augment already existing solar sail mission concepts and make novel mission concepts feasible.}, language = {en} } @inproceedings{KronigerHorikawaFunkeetal.2021, author = {Kroniger, Daniel and Horikawa, Atsushi and Funke, Harald and Pf{\"a}ffle, Franziska}, title = {Numerical investigation of micromix hydrogen flames at different combustor pressure levels}, series = {Proceedings of the International Conference on Power Engineering 2021}, booktitle = {Proceedings of the International Conference on Power Engineering 2021}, pages = {4 Seiten}, year = {2021}, abstract = {This study investigates the influence of pressure on the temperature distribution of the micromix (MMX) hydrogen flame and the NOx emissions. A steady computational fluid dynamic (CFD) analysis is performed by simulating a reactive flow with a detailed chemical reaction model. The numerical analysis is validated based on experimental investigations. A quantitative correlation is parametrized based on the numerical results. We find, that the flame initiation point shifts with increasing pressure from anchoring behind a downstream located bluff body towards anchoring upstream at the hydrogen jet. The numerical NOx emissions trend regarding to a variation of pressure is in good agreement with the experimental results. The pressure has an impact on both, the residence time within the maximum temperature region and on the peak temperature itself. In conclusion, the numerical model proved to be adequate for future prototype design exploration studies targeting on improving the operating range.}, language = {en} } @inproceedings{HorikawaOkadaYamaguchietal.2021, author = {Horikawa, Atsushi and Okada, Kunio and Yamaguchi, Masato and Aoki, Shigeki and Wirsum, Manfred and Funke, Harald and Kusterer, Karsten}, title = {Combustor development and engine demonstration of micro-mix hydrogen combustion applied to M1A-17 gas turbine}, series = {ASME Turbo Expo 2021: Turbomachinery Technical Conference and Exposition // Volume 3B: Combustion, Fuels, and Emissions}, booktitle = {ASME Turbo Expo 2021: Turbomachinery Technical Conference and Exposition // Volume 3B: Combustion, Fuels, and Emissions}, doi = {10.1115/GT2021-59666}, pages = {13 Seiten}, year = {2021}, abstract = {Kawasaki Heavy Industries, LTD. (KHI) has research and development projects for a future hydrogen society. These projects comprise the complete hydrogen cycle, including the production of hydrogen gas, the refinement and liquefaction for transportation and storage, and finally the utilization in a gas turbine for electricity and heat supply. Within the development of the hydrogen gas turbine, the key technology is stable and low NOx hydrogen combustion, namely the Dry Low NOx (DLN) hydrogen combustion. KHI, Aachen University of Applied Science, and B\&B-AGEMA have investigated the possibility of low NOx micro-mix hydrogen combustion and its application to an industrial gas turbine combustor. From 2014 to 2018, KHI developed a DLN hydrogen combustor for a 2MW class industrial gas turbine with the micro-mix technology. Thereby, the ignition performance, the flame stability for equivalent rotational speed, and higher load conditions were investigated. NOx emission values were kept about half of the Air Pollution Control Law in Japan: 84ppm (O2-15\%). Hereby, the elementary combustor development was completed. From May 2020, KHI started the engine demonstration operation by using an M1A-17 gas turbine with a co-generation system located in the hydrogen-fueled power generation plant in Kobe City, Japan. During the first engine demonstration tests, adjustments of engine starting and load control with fuel staging were investigated. On 21st May, the electrical power output reached 1,635 kW, which corresponds to 100\% load (ambient temperature 20 °C), and thereby NOx emissions of 65 ppm (O2-15, 60 RH\%) were verified. Here, for the first time, a DLN hydrogen-fueled gas turbine successfully generated power and heat.}, language = {en} } @inproceedings{Dachwald2004, author = {Dachwald, Bernd}, title = {Solar sail performance requirements for missions to the outer solar system and beyond}, series = {55th International Astronautical Congress 2004}, booktitle = {55th International Astronautical Congress 2004}, doi = {10.2514/6.IAC-04-S.P.11}, pages = {1 -- 9}, year = {2004}, abstract = {Solar sails enable missions to the outer solar system and beyond, although the solar radiation pressure decreases with the square of solar distance. For such missions, the solar sail may gain a large amount of energy by first making one or more close approaches to the sun. Within this paper, optimal trajectories for solar sail missions to the outer planets and into near interstellar space (200 AU) are presented. Thereby, it is shown that even near/medium-term solar sails with relatively moderate performance allow reasonable transfer times to the boundaries of the solar system.}, language = {en} } @inproceedings{SchopenShabaniEschetal.2022, author = {Schopen, Oliver and Shabani, Bahman and Esch, Thomas and Kemper, Hans and Shah, Neel}, title = {Quantitative evaluation of health management designs for fuel cell systems in transport vehicles}, series = {2nd UNITED-SAIG International Conference Proceedings}, booktitle = {2nd UNITED-SAIG International Conference Proceedings}, editor = {Rahim, S.A. and As'arry, A. and Zuhri, M.Y.M. and Harmin, M.Y. and Rezali, K.A.M. and Hairuddin, A.A.}, pages = {1 -- 3}, year = {2022}, abstract = {Focusing on transport vehicles, mainly with regard to aviation applications, this paper presents compilation and subsequent quantitative evaluation of methods aimed at building an optimum integrated health management solution for fuel cell systems. The methods are divided into two different main types and compiled in a related scheme. Furthermore, different methods are analysed and evaluated based on parameters specific to the aviation context of this study. Finally, the most suitable method for use in fuel cell health management systems is identified and its performance and suitability is quantified.}, language = {en} } @inproceedings{SchopenKemperEsch2021, author = {Schopen, Oliver and Kemper, Hans and Esch, Thomas}, title = {Development of a comparison methodology and evaluation matrix for electrically driven compressors in ICE and FC}, series = {Proceedings of the 1st UNITED - Southeast Asia Automotive Interest Group (SAIG) International Conference}, booktitle = {Proceedings of the 1st UNITED - Southeast Asia Automotive Interest Group (SAIG) International Conference}, publisher = {FH Joanneum}, address = {Graz}, isbn = {978-3-902103-94-9}, pages = {45 -- 46}, year = {2021}, abstract = {In addition to electromobility and alternative drive systems, a focus is set on electrically driven compressors (EDC), with a high potential for increasing the efficiency of internal combustion engines (ICE) and fuel cells [01]. The primary objective is to increase the ICE torque, provided independently of the ICE speed by compressing the intake air and consequently the ICE filling level supported by the compressor. For operation independent from the ICE speed, the EDC compressor is decoupled from the turbine by using an electric compressor motor (CM) instead of the turbine. ICE performances can be increased by the use of EDC where individual compressor parameters are adapted to the respective application area [02] [03]. This task contains great challenges, increased by demands with regard to pollutant reduction while maintaining constant performance and reduced fuel consumption. The FH-Aachen is equipped with an EDC test bench which enables EDC-investigations in various configurations and operating modes. Characteristic properties of different compressors can be determined, which build the basis for a comparison methodology. Subject of this project is the development of a comparison methodology for EDC with an associated evaluation method and a defined overall evaluation method. For the application of this comparison methodology, corresponding series of measurements are carried out on the EDC test bench using an appropriate test device.}, language = {en} } @inproceedings{VeettilRakshitSchopenetal.2022, author = {Veettil, Yadu Krishna Morassery and Rakshit, Shantam and Schopen, Oliver and Kemper, Hans and Esch, Thomas and Shabani, Bahman}, title = {Automated Control System Strategies to Ensure Safety of PEM Fuel Cells Using Kalman Filters}, series = {Proceedings of the 7th International Conference and Exhibition on Sustainable Energy and Advanced Materials (ICE-SEAM 2021), Melaka, Malaysia}, booktitle = {Proceedings of the 7th International Conference and Exhibition on Sustainable Energy and Advanced Materials (ICE-SEAM 2021), Melaka, Malaysia}, editor = {Bin Abdollah, Mohd Fadzli and Amiruddin, Hilmi and Singh, Amrik Singh Phuman and Munir, Fudhail Abdul and Ibrahim, Asriana}, publisher = {Springer Nature}, address = {Singapore}, isbn = {978-981-19-3178-9}, issn = {2195-4356}, doi = {10.1007/978-981-19-3179-6_55}, pages = {296 -- 299}, year = {2022}, abstract = {Having well-defined control strategies for fuel cells, that can efficiently detect errors and take corrective action is critically important for safety in all applications, and especially so in aviation. The algorithms not only ensure operator safety by monitoring the fuel cell and connected components, but also contribute to extending the health of the fuel cell, its durability and safe operation over its lifetime. While sensors are used to provide peripheral data surrounding the fuel cell, the internal states of the fuel cell cannot be directly measured. To overcome this restriction, Kalman Filter has been implemented as an internal state observer. Other safety conditions are evaluated using real-time data from every connected sensor and corrective actions automatically take place to ensure safety. The algorithms discussed in this paper have been validated thorough Model-in-the-Loop (MiL) tests as well as practical validation at a dedicated test bench.}, language = {en} } @inproceedings{TamaldinMansorMatYaminetal.2022, author = {Tamaldin, Noreffendy and Mansor, Muhd Rizuan and Mat Yamin, Ahmad Kamal and Bin Abdollah, Mohd Fazli and Esch, Thomas and Tonoli, Andrea and Reisinger, Karl Heinz and Sprenger, Hanna and Razuli, Hisham}, title = {Development of UTeM United Future Fuel Design Training Center Under Erasmus+ United Program}, series = {Proceedings of the 7th International Conference and Exhibition on Sustainable Energy and Advanced Materials (ICE-SEAM 2021), Melaka, Malaysia}, booktitle = {Proceedings of the 7th International Conference and Exhibition on Sustainable Energy and Advanced Materials (ICE-SEAM 2021), Melaka, Malaysia}, editor = {Bin Abdollah, Mohd Fadzli and Amiruddin, Hilmi and Singh, Amrik Singh Phuman and Munir, Fudhail Abdul and Ibrahim, Asriana}, publisher = {Springer Nature}, address = {Singapore}, isbn = {978-981-19-3178-9}, issn = {2195-4356}, doi = {10.1007/978-981-19-3179-6_50}, pages = {274 -- 278}, year = {2022}, abstract = {The industrial revolution IR4.0 era have driven many states of the art technologies to be introduced especially in the automotive industry. 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 is taking initiative to close the gap utilizing the Erasmus+ United grant from EU. A consortium was founded to engage with automotive technology transfer using the European ramework to Malaysian, Indonesian and Thailand Higher Education Institutions (HEI) as well as automotive industries. 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 Universityindustry 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} } @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} } @inproceedings{KreyerEsch2017, author = {Kreyer, J{\"o}rg and Esch, Thomas}, title = {Simulation Tool for Predictive Control Strategies for an ORCSystem in Heavy Duty Vehicles}, series = {European GT Conference 2017}, booktitle = {European GT Conference 2017}, pages = {16 Seiten}, year = {2017}, abstract = {Scientific questions - How can a non-stationary heat offering in the commercial vehicle be used to reduce fuel consumption? - Which potentials offer route and environmental information among with predicted speed and load trajectories to increase the efficiency of a ORC-System? Methods - Desktop bound holistic simulation model for a heavy duty truck incl. an ORC System - Prediction of massflows, temperatures and mixture quality (AFR) of exhaust gas}, language = {en} } @inproceedings{KemperHellenbroichEsch2009, author = {Kemper, Hans and Hellenbroich, Gereon and Esch, Thomas}, title = {Concept of an innovative passenger-car hybrid drive for European driving conditions}, series = {Hybrid vehicles and energy management : 6th symposium ; 18th and 19th February 2009, Stadthalle Braunschweig}, booktitle = {Hybrid vehicles and energy management : 6th symposium ; 18th and 19th February 2009, Stadthalle Braunschweig}, publisher = {Gesamtzentrum f{\"u}r Verkehr (GZVB)}, address = {Braunschweig}, isbn = {978-3-937655-20-8}, pages = {264 -- 287}, year = {2009}, abstract = {The downsizing of spark ignition engines in conjunction with turbocharging is considered to be a promising method for reducing CO₂ emissions. Using this concept, FEV has developed a new, highly efficient drivetrain to demonstrate fuel consumption reduction and drivability in a vehicle based on the Ford Focus ST. The newly designed 1.8L turbocharged gasoline engine incorporates infinitely variable intake and outlet control timing and direct fuel injection utilizing piezo injectors centrally located. In addition, this engine uses a prototype FEV engine control system, with software that was developed and adapted entirely by FEV. The vehicle features a 160 kW engine with a maximum mean effective pressure of 22.4 bar and 34 \% savings in simulated fuel consumption. During the first stage, a new electrohydraulically actuated hybrid transmission with seven forward gears and one reverse gear and a single dry starting clutch will be integrated. The electric motor of the hybrid is directly connected to the gear set of the transmission. Utilizing the special gear set layout, the electric motor can provide boost during a change of gears, so that there is no interruption in traction. Therefore, the transmission system combines the advantages of a double clutch controlled gear change (gear change without an interruption in traction) with the efficient, cost-effective design of an automated manual transmission system. Additionally, the transmission provides a purely electric drive system and the operation of an air-conditioning compressor during the engine stop phases. One other alternative is through the use of CAI (Controlled Auto Ignition), which incorporates a process developed by FEV for controlled compression ignition.}, language = {en} } @inproceedings{FunkeEschRoosen2009, author = {Funke, Harald and Esch, Thomas and Roosen, Peter}, title = {Using motor gasoline for aircrafts - coping with growing bio-fuel-caused risks by understanding cause-effect relationship}, series = {Fuels 2009 : mineral oil based and alternative fuels ; 7th international colloquium ; January 14 - 15, 2009}, booktitle = {Fuels 2009 : mineral oil based and alternative fuels ; 7th international colloquium ; January 14 - 15, 2009}, editor = {Bartz, Wilfried J.}, publisher = {Technische Akademie Esslingen (TAE)}, address = {Ostfildern}, isbn = {978-3-924813-75-8}, pages = {237 -- 244}, year = {2009}, abstract = {The utilisation of vehicle-oriented gasoline in general aviation is very desirable for both ecological and economical reasons, as well as for general considerations of availability. As of today vehicle fuels may be used if the respective engine and cell are certified for such an operation. For older planes a supplementary technical certificate is provided for gasoline mixtures with less than 1 \% v/v ethanol only, though. Larger admixtures of ethanol may lead to sudden engine malfunction and should be considered as considerable security risks. Major problems are caused by the partially ethanol non-withstanding materials, a necessarily changed stochiometric adjustment of the engine for varying ethanol shares and the tendency for phase separation in the presence of absorbed water. The concepts of the flexible fuel vehicles are only partially applicable in the view of air security.}, 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} } @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} } @inproceedings{ThomaStiemerBraunetal.2023, author = {Thoma, Andreas and Stiemer, Luc and Braun, Carsten and Fisher, Alex and Gardi, Alessandro G.}, title = {Potential of hybrid neural network local path planner for small UAV in urban environments}, series = {AIAA SCITECH 2023 Forum}, booktitle = {AIAA SCITECH 2023 Forum}, publisher = {AIAA}, doi = {10.2514/6.2023-2359}, pages = {13 Seiten}, year = {2023}, abstract = {This work proposes a hybrid algorithm combining an Artificial Neural Network (ANN) with a conventional local path planner to navigate UAVs efficiently in various unknown urban environments. The proposed method of a Hybrid Artificial Neural Network Avoidance System is called HANNAS. The ANN analyses a video stream and classifies the current environment. This information about the current Environment is used to set several control parameters of a conventional local path planner, the 3DVFH*. The local path planner then plans the path toward a specific goal point based on distance data from a depth camera. We trained and tested a state-of-the-art image segmentation algorithm, PP-LiteSeg. The proposed HANNAS method reaches a failure probability of 17\%, which is less than half the failure probability of the baseline and around half the failure probability of an improved, bio-inspired version of the 3DVFH*. The proposed HANNAS method does not show any disadvantages regarding flight time or flight distance.}, language = {en} } @inproceedings{HavermannSeilerHenning2010, author = {Havermann, Marc and Seiler, F. and Henning, P.}, title = {Shock Tunnel Experiments and CFD Simulation of Lateral Jet Interaction in Hypersonic Flows}, series = {New Results in Numerical and Experimental Fluid Mechanics VII; Contributions to the 16th STAB/DGLR Symposium Aachen, Germany 2008}, booktitle = {New Results in Numerical and Experimental Fluid Mechanics VII; Contributions to the 16th STAB/DGLR Symposium Aachen, Germany 2008}, editor = {Dillmann, Andreas and Heller, Gerd and Klaas, Michael and Kreplin, Hans-Peter and Nitsche, Wolfgang and Schr{\"o}der, Wolfgang}, publisher = {Springer}, address = {Berlin}, isbn = {9783642142437}, doi = {10.1007/978-3-642-14243-7_45}, pages = {365 -- 372}, year = {2010}, language = {en} }