TY - CHAP A1 - Thenent, N. E. A1 - Dahmann, Peter T1 - Increasing aircraft design flexibility ‐ The development of a hydrostatic transmission for gliders with self‐launching capability T2 - Deutscher Luft- und Raumfahrtkongress 2011 : Bremen, 27. bis 29. September 2011 ; Tagungsband Y1 - 2011 SN - 978-3-9321-8274-7 SP - 865 EP - 883 PB - Dt. Gesellschaft für Luft- und Raumfahrt CY - Bonn ER - TY - CHAP A1 - Thenent, N. E. A1 - Dahmann, Peter T1 - Hydrostatic propeller drive T2 - Proceedings of the conference : 18 - 20 May, 2011 Tampere, Finland / the Twelth Scandinavian International Conference on Fluid Power, SICFP'11. Ed.: Harri Sairiala ... Vol. 1 Y1 - 2011 SN - 978-952-15-2517-9 SP - 217 EP - 227 CY - Tampere ER - TY - CHAP A1 - Bagheri, Mohsen A1 - Schleupen, Josef A1 - Dahmann, Peter A1 - Kallweit, Stephan T1 - A multi-functional device applying for the safe maintenance at high-altitude on wind turbines T2 - 20th International Conference on Composite Materials : Copenhagen, 19 - 24th July 2015 Y1 - 2015 SP - 1 EP - 6 ER - TY - CHAP A1 - Schleupen, Josef A1 - Engemann, Heiko A1 - Bagheri, Mohsen A1 - Kallweit, Stephan A1 - Dahmann, Peter T1 - Developing a climbing maintenance robot for tower and rotor blade service of wind turbines T2 - Advances in Robot Design and Intelligent Control : Proceedings of the 25th Conference on Robotics in Alpe-Adria-Danube Region (RAAD16) Y1 - 2017 SN - 978-3-319-49058-8 U6 - http://dx.doi.org/10.1007/978-3-319-49058-8_34 N1 - Advances in Robot Design and Intelligent Control ; Vol. 540 SP - 310 EP - 319 PB - Springer CY - Cham ER - TY - CHAP A1 - Schildt, Philipp A1 - Marzocca, Pier A1 - Braun, Carsten A1 - Dahmann, Peter A1 - Keimer, Jona T1 - Effects of atmospheric excitation on vibration based condition monitoring methods for hybrid-electric aircraft propulsion systems T2 - AIAC 2018: 18th Australian International Aerospace Congress: HUMS - 11th Defence Science and Technology (DST) International Conference on Health and Usage Monitoring (HUMS 2019): ISSFD - 27th International Symposium on Space Flight Dynamics (ISSFD) Y1 - 2019 SN - 9781925627213 SP - 923 EP - 928 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 - TY - CHAP A1 - Hille, Sebastian A1 - Stumpf, Eike A1 - Mayntz, Joscha A1 - Dahmann, Peter T1 - Prediction of sound exposure caused by a landing motor glider with recuperating propellers T2 - AIAA SCITECH 2023 Forum N2 - 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. Y1 - 2023 U6 - http://dx.doi.org/10.2514/6.2023-0211 N1 - AIAA SCITECH 2023 Forum, 23-27 January 2023, National Harbor, MD & Online PB - AIAA ER - TY - JOUR A1 - Hammer, Thorben A1 - Quitter, Julius A1 - Mayntz, Joscha A1 - Bauschat, J.-Michael A1 - Dahmann, Peter A1 - Götten, Falk A1 - Hille, S. A1 - Stumpf, E. T1 - Free fall drag estimation of small-scale multirotor unmanned aircraft systems using computational fluid dynamics and wind tunnel experiments JF - CEAS Aeronautical Journal N2 - New European Union (EU) regulations for UAS operations require an operational risk analysis, which includes an estimation of the potential danger of the UAS crashing. A key parameter for the potential ground risk is the kinetic impact energy of the UAS. The kinetic energy depends on the impact velocity of the UAS and, therefore, on the aerodynamic drag and the weight during free fall. Hence, estimating the impact energy of a UAS requires an accurate drag estimation of the UAS in that state. The paper at hand presents the aerodynamic drag estimation of small-scale multirotor UAS. Multirotor UAS of various sizes and configurations were analysed with a fully unsteady Reynolds-averaged Navier–Stokes approach. These simulations included different velocities and various fuselage pitch angles of the UAS. The results were compared against force measurements performed in a subsonic wind tunnel and provided good consistency. Furthermore, the influence of the UAS`s fuselage pitch angle as well as the influence of fixed and free spinning propellers on the aerodynamic drag was analysed. Free spinning propellers may increase the drag by up to 110%, depending on the fuselage pitch angle. Increasing the fuselage pitch angle of the UAS lowers the drag by 40% up to 85%, depending on the UAS. The data presented in this paper allow for increased accuracy of ground risk assessments. KW - Multirotor UAS KW - Drag estimation KW - CFD KW - Wind tunnel experiments KW - Wind milling Y1 - 2023 U6 - http://dx.doi.org/10.1007/s13272-023-00702-w SN - 1869-5590 (Online) SN - 1869-5582 (Print) N1 - Corresponding author: Thorben Hammer PB - Springer CY - Wien ER -