TY - CHAP A1 - Finger, Felix A1 - Braun, Carsten A1 - Bil, Cees T1 - Comparative assessment of parallel-hybrid-electric propulsion systems for four different aircraft T2 - AIAA SciTech Forum 2020, 06.01.2020 - 10.01.2020, Orlando Y1 - 2020 U6 - http://dx.doi.org/10.2514/6.2020-1502 ER - TY - JOUR A1 - Finger, Felix A1 - Braun, Carsten A1 - Bil, Cees T1 - Impact of Battery Performance on the Initial Sizing of Hybrid-Electric General Aviation Aircraft JF - Journal of Aerospace Engineering N2 - Studies suggest that hybrid-electric aircraft have the potential to generate fewer emissions and be inherently quieter when compared to conventional aircraft. By operating combustion engines together with an electric propulsion system, synergistic benefits can be obtained. However, the performance of hybrid-electric aircraft is still constrained by a battery’s energy density and discharge rate. In this paper, the influence of battery performance on the gross mass for a four-seat general aviation aircraft with a hybrid-electric propulsion system is analyzed. For this design study, a high-level approach is chosen, using an innovative initial sizing methodology to determine the minimum required aircraft mass for a specific set of requirements and constraints. Only the peak-load shaving operational strategy is analyzed. Both parallel- and serial-hybrid propulsion configurations are considered for two different missions. The specific energy of the battery pack is varied from 200 to 1,000 W⋅h/kg, while the discharge time, and thus the normalized discharge rating (C-rating), is varied between 30 min (2C discharge rate) and 2 min (30C discharge rate). With the peak-load shaving operating strategy, it is desirable for hybrid-electric aircraft to use a light, low capacity battery system to boost performance. For this case, the battery’s specific power rating proved to be of much higher importance than for full electric designs, which have high capacity batteries. Discharge ratings of 20C allow a significant take-off mass reduction aircraft. The design point moves to higher wing loadings and higher levels of hybridization if batteries with advanced technology are used. Y1 - 2020 U6 - http://dx.doi.org/10.1061/(ASCE)AS.1943-5525.0001113 SN - 1943-5525 VL - 33 IS - 3 PB - ASCE CY - Reston, Va. ER - TY - CHAP A1 - Finger, Felix A1 - de Vries, Reynard A1 - Vos, Roelof A1 - Braun, Carsten A1 - Bil, Cees T1 - A comparison of hybrid-electric aircraft sizing methods T2 - AIAA Scitech 2020 Forum Y1 - 2020 U6 - http://dx.doi.org/10.2514/6.2020-1006 N1 - AIAA Scitech 2020 Forum, Driving aerospace solutions for global challenges, Orlando, 06. - 10. January 2020 ER - TY - JOUR A1 - Finger, Felix A1 - Götten, Falk T1 - Neue Ansätze für die Entwicklung von unbemannten Fluggeräten JF - Ingenieurspiegel N2 - Wie sieht das unbemannte Flugzeug von Übermorgen aus? Dieser Frage stellen sich Forscher an der Fachhochschule Aachen. Die weltweit rasant fortschreitende Entwicklung des Marktes für unbemannte Fluggeräte (UAVs - „Unmanned Aerial Vehicles“) bietet großes Potenzial für Wachstum und Wertschöpfung. Unbemannte fliegende Systeme können – für bestimmte Anwendungsgebiete – wesentlich günstiger, kleiner und effizienter ausgelegt werden als bemannte Lösungen. Dabei sind sich viele Unternehmen über das mögliche Potential dieser Technologie noch gar nicht bewusst. Y1 - 2019 SN - 1868-5919 N1 - Project: UAV Design VL - 2019 IS - 1 SP - 67 EP - 68 ER - TY - CHAP A1 - Finger, Felix A1 - Götten, Falk A1 - Braun, Carsten T1 - Initial Sizing for a Family of Hybrid-Electric VTOL General Aviation Aircraft T2 - 67. Deutscher Luft- und Raumfahrtkongress 2018 Y1 - 2018 ER - TY - CHAP A1 - Finger, Felix A1 - Götten, Falk A1 - Braun, Carsten A1 - Bil, C. T1 - On Aircraft Design Under the Consideration of Hybrid-Electric Propulsion Systems T2 - APISAT 2018: The Proceedings of the 2018 Asia-Pacific International Symposium on Aerospace Technology (APISAT 2018) N2 - 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. KW - Hybrid-electric aircraft KW - Aircraft design KW - Design rules KW - Green aircraft Y1 - 2019 SN - 978-981-13-3305-7 U6 - http://dx.doi.org/10.1007/978-981-13-3305-7_99 N1 - APISAT 2018 - Asia-Pacific International Symposium on Aerospace Technology. 16-18 October 2018. Chengdu, China. Lecture Notes in Electrical Engineering (LNEE, volume 459) SP - 1261 EP - 1272 PB - Springer CY - Singapore ER - TY - CHAP A1 - Finger, Felix A1 - Götten, Falk A1 - Braun, Carsten A1 - Bil, Cees T1 - Mass, Primary Energy, and Cost - The Impact of Optimization Objectives on the Initial Sizing of Hybrid-Electric General Aviation Aircraft T2 - Deutscher Luft- und Raumfahrtkongress 2019, DLRK 2019. Darmstadt, Germany Y1 - 2019 U6 - http://dx.doi.org/10.25967/490012 SP - 1 EP - 17 ER - TY - JOUR A1 - Finger, Felix A1 - Götten, Falk A1 - Braun, Carsten A1 - Bil, Cees T1 - Mass, primary energy, and cost: the impact of optimization objectives on the initial sizing of hybrid-electric general aviation aircraft JF - CEAS Aeronautical Journal N2 - For short take-off and landing (STOL) aircraft, a parallel hybrid-electric propulsion system potentially offers superior performance compared to a conventional propulsion system, because the short-take-off power requirement is much higher than the cruise power requirement. This power-matching problem can be solved with a balanced hybrid propulsion system. However, there is a trade-off between wing loading, power loading, the level of hybridization, as well as range and take-off distance. An optimization method can vary design variables in such a way that a minimum of a particular objective is attained. In this paper, a comparison between the optimization results for minimum mass, minimum consumed primary energy, and minimum cost is conducted. A new initial sizing algorithm for general aviation aircraft with hybrid-electric propulsion systems is applied. This initial sizing methodology covers point performance, mission performance analysis, the weight estimation process, and cost estimation. The methodology is applied to the design of a STOL general aviation aircraft, intended for on-demand air mobility operations. The aircraft is sized to carry eight passengers over a distance of 500 km, while able to take off and land from short airstrips. Results indicate that parallel hybrid-electric propulsion systems must be considered for future STOL aircraft. Y1 - 2020 U6 - http://dx.doi.org/10.1007/s13272-020-00449-8 SN - 1869-5590 N1 - Corresponding author: Felix Finger VL - 2020 IS - 11 SP - 713 EP - 730 PB - Springer CY - Heidelberg ER - TY - CHAP A1 - Finger, Felix A1 - Götten, Falk A1 - Braun, Carsten A1 - Bil, Cees T1 - Cost Estimation Methods for Hybrid-Electric General Aviation Aircraft T2 - Asia Pacific International Symposium on Aerospace Technology. APISAT 2019 Y1 - 2019 SP - 1 EP - 13 ER - TY - CHAP A1 - Finger, Felix A1 - Khalsa, R. A1 - Kreyer, Jörg A1 - Mayntz, Joscha A1 - Braun, Carsten A1 - Dahmann, Peter A1 - Esch, Thomas A1 - Kemper, Hans A1 - Schmitz, O. A1 - Bragard, Michael T1 - An approach to propulsion system modelling for the conceptual design of hybrid-electric general aviation aircraft T2 - Deutscher Luft- und Raumfahrtkongress 2019, 30.9.-2.10.2019, Darmstadt N2 - 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. Y1 - 2019 ER -