@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{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{BergmannGoettenBraunetal.2022, author = {Bergmann, Ole and G{\"o}tten, Falk and Braun, Carsten and Janser, Frank}, title = {Comparison and evaluation of blade element methods against RANS simulations and test data}, series = {CEAS Aeronautical Journal}, volume = {13}, booktitle = {CEAS Aeronautical Journal}, publisher = {Springer}, address = {Wien}, issn = {1869-5590 (Online)}, doi = {10.1007/s13272-022-00579-1}, pages = {535 -- 557}, year = {2022}, abstract = {This paper compares several blade element theory (BET) method-based propeller simulation tools, including an evaluation against static propeller ground tests and high-fidelity Reynolds-Average Navier Stokes (RANS) simulations. Two proprietary propeller geometries for paraglider applications are analysed in static and flight conditions. The RANS simulations are validated with the static test data and used as a reference for comparing the BET in flight conditions. The comparison includes the analysis of varying 2D aerodynamic airfoil parameters and different induced velocity calculation methods. The evaluation of the BET propeller simulation tools shows the strength of the BET tools compared to RANS simulations. The RANS simulations underpredict static experimental data within 10\% relative error, while appropriate BET tools overpredict the RANS results by 15-20\% relative error. A variation in 2D aerodynamic data depicts the need for highly accurate 2D data for accurate BET results. The nonlinear BET coupled with XFOIL for the 2D aerodynamic data matches best with RANS in static operation and flight conditions. The novel BET tool PropCODE combines both approaches and offers further correction models for highly accurate static and flight condition results.}, language = {en} } @article{GoettenHavermannBraunetal.2020, author = {G{\"o}tten, Falk and Havermann, Marc and Braun, Carsten and Marino, Matthew and Bil, Cees}, title = {Airfoil drag at low-to-medium reynolds numbers: A novel estimation method}, series = {AIAA Journal}, volume = {58}, journal = {AIAA Journal}, number = {7}, publisher = {AIAA}, address = {Reston, Va.}, issn = {1533-385X}, doi = {10.2514/1.J058983}, pages = {2791 -- 2805}, year = {2020}, abstract = {This paper presents a novel method for airfoil drag estimation at Reynolds numbers between 4×10⁵ and 4×10⁶. The novel method is based on a systematic study of 40 airfoils applying over 600 numerical simulations and considering natural transition. The influence of the airfoil thickness-to-chord ratio, camber, and freestream Reynolds number on both friction and pressure drag is analyzed in detail. Natural transition significantly affects drag characteristics and leads to distinct drag minima for different Reynolds numbers and thickness-to-chord ratios. The results of the systematic study are used to develop empirical correlations that can accurately predict an airfoil drag at low-lift conditions. The new approach estimates a transition location based on airfoil thickness-to-chord ratio, camber, and Reynolds number. It uses the transition location in a mixed laminar-turbulent skin-friction calculation, and corrects the skin-friction coefficient for separation effects. Pressure drag is estimated separately based on correlations of thickness-to-chord ratio, camber, and Reynolds number. The novel method shows excellent accuracy when compared with wind-tunnel measurements of multiple airfoils. It is easily integrable into existing aircraft design environments and is highly beneficial in the conceptual design stage.}, language = {en} } @article{GoettenHavermannBraunetal.2021, author = {G{\"o}tten, Falk and Havermann, Marc and Braun, Carsten and Marino, Matthew and Bil, Cees}, title = {Aerodynamic Investigations of UAV Sensor Turrets - A Combined Wind-tunnel and CFD Approach}, series = {SciTech 2021, AIAA SciTech Forum, online, WW, Jan 11-15, 2021}, journal = {SciTech 2021, AIAA SciTech Forum, online, WW, Jan 11-15, 2021}, publisher = {AIAA}, address = {Reston, Va.}, doi = {10.2514/6.2021-1535}, pages = {1 -- 12}, year = {2021}, 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{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{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} }