@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{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{RingsLudowicyFingeretal.2019, author = {Rings, Ren{\´e} and Ludowicy, Jonas and Finger, Felix and Braun, Carsten and Bil, Cees}, title = {Sensitivity Analysis of General Aviation Aircraft with Parallel Hybrid-Electric Propulsion Systems}, 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{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} } @article{FingerBilBraun2019, author = {Finger, Felix and Bil, Cees and Braun, Carsten}, title = {Initial Sizing Methodology for Hybrid-Electric General Aviation Aircraft}, series = {Journal of Aircraft}, volume = {57}, journal = {Journal of Aircraft}, number = {2}, issn = {1533-3868}, doi = {10.2514/1.C035428}, pages = {245 -- 255}, year = {2019}, language = {en} } @inproceedings{FingerGoettenBraunetal.2019, author = {Finger, Felix and G{\"o}tten, Falk and Braun, Carsten and Bil, Cees}, title = {Mass, Primary Energy, and Cost - The Impact of Optimization Objectives on the Initial Sizing of Hybrid-Electric General Aviation Aircraft}, series = {Deutscher Luft- und Raumfahrtkongress 2019, DLRK 2019. Darmstadt, Germany}, booktitle = {Deutscher Luft- und Raumfahrtkongress 2019, DLRK 2019. Darmstadt, Germany}, doi = {10.25967/490012}, pages = {1 -- 17}, year = {2019}, language = {en} } @inproceedings{GoettenFingerHavermannetal.2019, author = {G{\"o}tten, Falk and Finger, Felix and Havermann, Marc and Braun, Carsten and Marino, Matthew and Bil, Cees}, title = {A highly automated method for simulating airfoil characteristics at low Reynolds number using a RANS - transition approach}, series = {Deutscher Luft- und Raumfahrtkongress - DLRK 2019. Darmstadt, Germany}, booktitle = {Deutscher Luft- und Raumfahrtkongress - DLRK 2019. Darmstadt, Germany}, doi = {10.25967/490026}, pages = {1 -- 14}, year = {2019}, language = {en} } @inproceedings{FingerBraunBil2019, author = {Finger, Felix and Braun, Carsten and Bil, Cees}, title = {Impact of Engine Failure Constraints on the Initial Sizing of Hybrid-Electric GA Aircraft}, series = {AIAA Scitech 2019 Forum}, booktitle = {AIAA Scitech 2019 Forum}, doi = {10.2514/6.2019-1812}, year = {2019}, language = {en} } @article{GoettenHavermannBraunetal.2019, author = {G{\"o}tten, Falk and Havermann, Marc and Braun, Carsten and Gomez, Francisco and Bil, Cees}, title = {RANS Simulation Validation of a Small Sensor Turret for UAVs}, series = {Journal of Aerospace Engineering}, volume = {32}, journal = {Journal of Aerospace Engineering}, number = {5}, publisher = {ASCE}, address = {New York}, issn = {1943-5525}, doi = {10.1061/(ASCE)AS.1943-5525.0001055}, pages = {Article number 04019060}, year = {2019}, abstract = {Recent Unmanned Aerial Vehicle (UAV) design procedures rely on full aircraft steady-state Reynolds-Averaged-Navier-Stokes (RANS) analyses in early design stages. Small sensor turrets are included in such simulations, even though their aerodynamic properties show highly unsteady behavior. Very little is known about the effects of this approach on the simulation outcomes of small turrets. Therefore, the flow around a model turret at a Reynolds number of 47,400 is simulated with a steady-state RANS approach and compared to experimental data. Lift, drag, and surface pressure show good agreement with the experiment. The RANS model predicts the separation location too far downstream and shows a larger recirculation region aft of the body. Both characteristic arch and horseshoe vortex structures are visualized and qualitatively match the ones found by the experiment. The Reynolds number dependence of the drag coefficient follows the trend of a sphere within a distinct range. The outcomes indicate that a steady-state RANS model of a small sensor turret is able to give results that are useful for UAV engineering purposes but might not be suited for detailed insight into flow properties.}, language = {en} } @inproceedings{GoettenHavermannBraunetal.2018, author = {G{\"o}tten, Falk and Havermann, Marc and Braun, Carsten and Gomez, Francisco and Bil, Cees}, title = {On the Applicability of Empirical Drag Estimation Methods for Unmanned Air Vehicle Design Read More: https://arc.aiaa.org/doi/10.2514/6.2018-3192}, series = {2018 Aviation Technology, Integration, and Operations Conference, AIAA AVIATION Forum}, booktitle = {2018 Aviation Technology, Integration, and Operations Conference, AIAA AVIATION Forum}, issn = {1533-385X}, doi = {10.2514/6.2018-3192}, pages = {Article 3192}, year = {2018}, language = {en} } @article{FingerBraunBil2018, author = {Finger, Felix and Braun, Carsten and Bil, Cees}, title = {Impact of electric propulsion technology and mission requirements on the performance of VTOL UAVs}, series = {CEAS Aeronautical Journal}, volume = {10}, journal = {CEAS Aeronautical Journal}, number = {3}, publisher = {Springer}, issn = {1869-5582 print}, doi = {10.1007/s13272-018-0352-x}, pages = {843}, year = {2018}, abstract = {One of the engineering challenges in aviation is the design of transitioning vertical take-off and landing (VTOL) aircraft. Thrust-borne flight implies a higher mass fraction of the propulsion system, as well as much increased energy consumption in the take-off and landing phases. This mass increase is typically higher for aircraft with a separate lift propulsion system than for aircraft that use the cruise propulsion system to support a dedicated lift system. However, for a cost-benefit trade study, it is necessary to quantify the impact the VTOL requirement and propulsion configuration has on aircraft mass and size. For this reason, sizing studies are conducted. This paper explores the impact of considering a supplemental electric propulsion system for achieving hovering flight. Key variables in this study, apart from the lift system configuration, are the rotor disk loading and hover flight time, as well as the electrical systems technology level for both batteries and motors. Payload and endurance are typically used as the measures of merit for unmanned aircraft that carry electro-optical sensors, and therefore the analysis focuses on these particular parameters.}, language = {en} } @inproceedings{FingerBraunBil2018, author = {Finger, Felix and Braun, Carsten and Bil, Cees}, title = {Case studies in initial sizing for hybrid-electric general aviation aircraft}, series = {2018 AIAA/IEEE Electric Aircraft Technologies Symposium, Cincinnati, Ohio}, booktitle = {2018 AIAA/IEEE Electric Aircraft Technologies Symposium, Cincinnati, Ohio}, doi = {10.2514/6.2018-5005}, year = {2018}, language = {en} } @inproceedings{FingerBraunBil2018, author = {Finger, Felix and Braun, Carsten and Bil, Cees}, title = {An Initial Sizing Methodology for Hybrid-Electric Light Aircraft}, series = {AIAA AVIATION Forum 2018 Aviation Technology, Integration, and Operations Conference, Atlanta, Georgia, June 25 - 29, 2018}, booktitle = {AIAA AVIATION Forum 2018 Aviation Technology, Integration, and Operations Conference, Atlanta, Georgia, June 25 - 29, 2018}, doi = {10.2514/6.2018-4229}, year = {2018}, language = {en} } @inproceedings{FingerBraunBil2017, author = {Finger, Felix and Braun, Carsten and Bil, Cees}, title = {A Review of Configuration Design for Distributed Propulsion Transitioning VTOL Aircraft}, series = {Asia-Pacific International Symposium on Aerospace Technology 2017, APISAT 2017, Seoul, Korea}, booktitle = {Asia-Pacific International Symposium on Aerospace Technology 2017, APISAT 2017, Seoul, Korea}, pages = {15 Seiten}, year = {2017}, language = {en} } @inproceedings{FingerBraunBil2017, author = {Finger, Felix and Braun, Carsten and Bil, Cees}, title = {The Impact of Electric Propulsion on the Performance of VTOL UAVs}, series = {Deutscher Luft- und Raumfahrtkongress 2017, DLRK , M{\"u}nchen}, booktitle = {Deutscher Luft- und Raumfahrtkongress 2017, DLRK , M{\"u}nchen}, year = {2017}, language = {en} }