@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{GoettenFinger2019,
  author    = {G{\"o}tten, Falk and Finger, Felix},
  title     = {Conceptual Design of a Modular 150 kg Vertical Take-off and Landing Unmanned Aerial Vehicle},
  series = {Deutscher Luft- und Raumfahrtkongress - DLRK 2019. Darmstadt, Germany},
  booktitle = {Deutscher Luft- und Raumfahrtkongress - DLRK 2019. Darmstadt, Germany},
  pages     = {1 -- 10},
  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{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{HailerWeberArent2019,
  author    = {Hailer, Benjamin and Weber, Tobias and Arent, Jan-Christoph},
  title     = {Manufacturing Process Simulation for Autoclave-Produced Sandwich Structures},
  series = {Proceedings of SAMPE Europe Conference 2019, Nantes, France},
  booktitle = {Proceedings of SAMPE Europe Conference 2019, Nantes, France},
  pages     = {1 -- 8},
  year      = {2019},
  language  = {en}
}
@inproceedings{WeberEnglhardHaileretal.2019,
  author    = {Weber, Tobias and Englhard, Markus and Hailer, Benjamin and Arent, Jan-Christoph},
  title     = {Manufacturing Process Simulation for the Prediction of Tool-Part-Interaction and Ply Wrinkling},
  series = {Proceedings of SAMPE Europe Conference 2019, Nantes, France},
  booktitle = {Proceedings of SAMPE Europe Conference 2019, Nantes, France},
  pages     = {1 -- 10},
  year      = {2019},
  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{GrundmannBauerBodenetal.2019,
  author    = {Grundmann, Jan Thimo and Bauer, Waldemar and Boden, Ralf Christian and Ceriotti, Matteo and Cordero, Federico and Dachwald, Bernd and Dumont, Etienne and Grimm, Christian D. and Hercik, D. and Herique, A. and Ho, Tra-Mi and Jahnke, Rico and Kofman, Wlodek and Lange, Caroline and Lichtenheldt, Roy and McInnes, Colin R. and Mikschl, Tobias and Montenegro, Sergio and Moore, Iain and Pelivan, Ivanka and Peloni, Alessandro and Plettenmeier, Dirk and Quantius, Dominik and Reershemius, Siebo and Renger, Thomas and Riemann, Johannes and Rogez, Yves and Ruffer, Michael and Sasaki, Kaname and Schmitz, Nicole and Seboldt, Wolfgang and Seefeldt, Patric and Spietz, Peter and Spr{\"o}witz, Tom and Sznajder, Maciej and Toth, Norbert and Viavattene, Giulia and Wejmo, Elisabet and Wolff, Friederike and Ziach, Christian},
  title     = {Responsive exploration and asteroid characterization through integrated solar sail and lander development using small spacecraft technologies},
  series = {IAA Planetary Defense Conference},
  booktitle = {IAA Planetary Defense Conference},
  year      = {2019},
  abstract  = {In parallel to the evolution of the Planetary Defense Conference, the exploration of small solar system bodies has advanced from fast fly-bys on the sidelines of missions to the planets to the implementation of dedicated sample-return and in-situ analysis missions. Spacecraft of all sizes have landed, touch-and-go sampled, been gently beached, or impacted at hypervelocity on asteroid and comet surfaces. More have flown by close enough to image their surfaces in detail or sample their immediate environment, often as part of an extended or re-purposed mission. And finally, full-scale planetary defense experiment missions are in the making. Highly efficient low-thrust propulsion is increasingly applied beyond commercial use also in mainstream and flagship science missions, in combination with gravity assist propulsion. Another development in the same years is the growth of small spacecraft solutions, not in size but in numbers and individual capabilities. The on-going NASA OSIRIS-REx and JAXA HAYABUSA2 missions exemplify the trend as well as the upcoming NEA SCOUT mission or the landers MINERVA-II and MASCOT recently deployed on Ryugu. We outline likely as well as possible and efficient routes of continuation of all these developments towards a propellant-less and highly efficient class of spacecraft for small solar system body exploration: small spacecraft solar sails designed for carefree handling and equipped with carried landers and application modules, for all asteroid user communities -planetary science, planetary defence, and in-situ resource utilization. This projection builds on the experience gained in the development of deployable membrane structures leading up to the successful ground deployment test of a (20 m)² solar sail at DLR Cologne and in the 20 years since. It draws on the background of extensive trajectory optimization studies, the qualified technology of the DLR GOSSAMER-1 deployment demonstrator, and the MASCOT asteroid lander. These enable 'now-term' as well as near-term hardware solutions, and thus responsive fast-paced development. Mission types directly applicable to planetary defense include: single and Multiple NEA Rendezvous ((M)NR) for mitigation precursor, target monitoring and deflection follow-up tasks; sail-propelled head-on retrograde kinetic impactors (RKI) for mitigation; and deployable membrane based methods to modify the asteroid's properties or interact with it. The DLR-ESTEC GOSSAMER Roadmap initiated studies of missions uniquely feasible with solar sails such as Displaced L1 (DL1) space weather advance warning and monitoring and Solar Polar Orbiter (SPO) delivery which demonstrate the capability of near-term solar sails to achieve NEA rendezvous in any kind of orbit, from Earth-coorbital to extremely inclined and even retrograde orbits. For those mission types using separable payloads, such as SPO, (M)NR and RKI, design concepts can be derived from the separable Boom Sail Deployment Units characteristic of DLR GOSSAMER solar sail technology, nanolanders like MASCOT, or microlanders like the JAXA-DLR Jupiter Trojan Asteroid Lander for the OKEANOS mission which can shuttle from the sail to the asteroids visited and enable multiple NEA sample-return missions. These are an ideal match for solar sails in micro-spacecraft format whose launch configurations are compatible with ESPA and ASAP secondary payload platforms.},
  language  = {en}
}
@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{LudowicyRingsFingeretal.2019,
  author    = {Ludowicy, Jonas and Rings, Ren{\´e} and Finger, Felix and Braun, Carsten and Bil, Cees},
  title     = {Impact of Propulsion Technology Levels on the Sizing and Energy Consumption for Serial HybridElectric General Aviation Aircraft},
  series = {Asia Pacific International Symposium on Aerospace Technology. APISAT 2019},
  booktitle = {Asia Pacific International Symposium on Aerospace Technology. APISAT 2019},
  pages     = {14 Seiten},
  year      = {2019},
  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{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{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},
  abstract  = {This paper presents an approach for UAV propulsion system qualification and validation on the example of FH Aachen's 25 kg cargo UAV "PhoenAIX". Thrust and power consumption are the most important aspects of a propulsion system's layout. In the initial design phase, manufacturers' data has to be trusted, but the validation of components is an essential step in the design process. This process is presented in this paper. The vertical takeoff system is designed for efficient hover; therefore, performance under static conditions is paramount. Because an octo-copter layout with coaxial rotors is considered, the impact of this design choice is analyzed. Data on thrust, voltage stability, power consumption, rotational speed, and temperature development of motors and controllers are presented for different rotors. The fixed-wing propulsion system is designed for efficient cruise flight. At the same time, a certain static thrust has to be provided, as the aircraft needs to accelerate to cruise speed. As for the hover-system, data on different propellers is compared. The measurements were taken for static conditions, as well as for different inflow velocities, using the FH-Aachen's wind-tunnel.},
  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 = {CEAS Aeronautical Journal},
  volume    = {12},
  booktitle = {CEAS Aeronautical Journal},
  publisher = {Springer},
  address   = {Wien},
  issn      = {1869-5590},
  doi       = {10.1007/s13272-021-00522-w},
  pages     = {589 -- 603},
  year      = {2020},
  abstract  = {The paper presents the derivation of a new equivalent skin friction coefficient for estimating the parasitic drag of short-to-medium range fixed-wing unmanned aircraft. The new coefficient is derived from an aerodynamic analysis of ten different unmanned aircraft used on surveillance, reconnaissance, and search and rescue missions. The aircraft are simulated using a validated unsteady Reynolds-averaged Navier Stokes approach. The UAV's parasitic drag is significantly influenced by the presence of miscellaneous components like fixed landing gears or electro-optical sensor turrets. These components are responsible for almost half of an unmanned aircraft's total parasitic drag. The new equivalent skin friction coefficient accounts for these effects and is significantly higher compared to other aircraft categories. It is used to initially size an unmanned aircraft for a typical reconnaissance mission. The improved parasitic drag estimation yields a much heavier unmanned aircraft when compared to the sizing results using available drag data of manned aircraft.},
  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 2020 Forum},
  booktitle = {AIAA Scitech 2020 Forum},
  doi       = {10.2514/6.2020-1502},
  pages     = {15 Seiten},
  year      = {2020},
  abstract  = {As battery technologies advance, electric propulsion concepts are on the edge of disrupting aviation markets. However, until electric energy storage systems are ready to allow fully electric aircraft, the combination of combustion engine and electric motor as a hybrid-electric propulsion system seems to be a promising intermediate solution. Consequently, the design space for future aircraft is expanded considerably, as serial-hybrid-, parallel-hybrid-, fully-electric, and conventional propulsion systems must all be considered. While the best propulsion system depends on a multitude of requirements and considerations, trends can be observed for certain types of aircraft and certain types of missions. This paper provides insight into some factors that drive a new design towards either conventional or hybrid propulsion systems. General aviation aircraft, VTOL air taxis, transport aircraft, and UAVs are chosen as case studies. Typical missions for each class are considered, and the aircraft are analyzed regarding their take-off mass and primary energy consumption. For these case studies, a high-level approach is chosen, using an initial sizing methodology. Results indicate that hybrid-electric propulsion systems should be considered if the propulsion system is sized by short-duration power constraints (e.g. take-off, climb). However, if the propulsion system is sized by a continuous power requirement (e.g. cruise), hybrid-electric systems offer hardly any benefit.},
  language  = {en}
}
@inproceedings{GeibenGoettenHavermann2020,
  author    = {Geiben, Benedikt and G{\"o}tten, Falk and Havermann, Marc},
  title     = {Aerodynamic analysis of a winged sub-orbital spaceplane},
  publisher = {DGLR},
  address   = {Bonn},
  doi       = {10.25967/530170},
  year      = {2020},
  abstract  = {This paper primarily presents an aerodynamic CFD analysis of a winged spaceplane geometry based on the Japanese Space Walker proposal. StarCCM was used to calculate aerodynamic coefficients for a typical space flight trajectory including super-, trans- and subsonic Mach numbers and two angles of attack. Since the solution of the RANS equations in such supersonic flight regimes is still computationally expensive, inviscid Euler simulations can principally lead to a significant reduction in computational effort. The impact on accuracy of aerodynamic properties is further analysed by comparing both methods for different flight regimes up to a Mach number of 4.},
  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{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},
  publisher = {DGLR},
  address   = {Bonn},
  doi       = {10.25967/490162},
  pages     = {13 Seiten},
  year      = {2020},
  abstract  = {In addition to very high safety and reliability requirements, the design of internal combustion engines (ICE) in aviation focuses on economic efficiency. The objective must be to design the aircraft powertrain optimized for a specific flight mission with respect to fuel consumption and specific engine power. Against this background, expert tools provide valuable decision-making assistance for the customer. In this paper, a mathematical calculation model for the fuel consumption of aircraft ICE is presented. This model enables the derivation of fuel consumption maps for different engine configurations. Depending on the flight conditions and based on these maps, the current and the integrated fuel consumption for freely definable flight emissions is calculated. For that purpose, an interpolation method is used, that has been optimized for accuracy and calculation time. The mission boundary conditions flight altitude and power requirement of the ICE form the basis for this calculation. The mathematical fuel consumption model is embedded in a parent program. This parent program presents the simulated fuel consumption by means of an example flight mission for a representative airplane. The focus of the work is therefore on reproducing exact consumption data for flight operations. By use of the empirical approaches according to Gagg-Farrar [1] the power and fuel consumption as a function of the flight altitude are determined. To substantiate this approaches, a 1-D ICE model based on the multi-physical simulation tool GT-Suite® has been created. This 1-D engine model offers the possibility to analyze the filling and gas change processes, the internal combustion as well as heat and friction losses for an ICE under altitude environmental conditions. Performance measurements on a dynamometer at sea level for a naturally aspirated ICE with a displacement of 1211 ccm used in an aviation aircraft has been done to validate the 1-D ICE model. To check the plausibility of the empirical approaches with respect to the fuel consumption and performance adjustment for the flight altitude an analysis of the ICE efficiency chain of the 1-D engine model is done. In addition, a comparison of literature and manufacturer data with the simulation results is presented.},
  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{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"},
  doi       = {10.25967/530183},
  pages     = {10 Seiten},
  year      = {2020},
  language  = {en}
}