TY  - JOUR
A1  - Hammer, Thorben
A1  - Quitter, Julius
A1  - Mayntz, Joscha
A1  - Bauschat, J.-Michael
A1  - Dahmann, Peter
A1  - Götten, Falk
A1  - Hille, Sebastian
A1  - Stumpf, Eike
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  - https://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  - 
TY  - CHAP
A1  - Ludowicy, Jonas
A1  - Rings, René
A1  - Finger, Felix
A1  - Braun, Carsten
A1  - Bil, Cees
T1  - Impact of Propulsion Technology Levels on the Sizing and Energy Consumption for Serial HybridElectric General Aviation Aircraft
T2  - Asia Pacific International Symposium on Aerospace Technology. APISAT 2019
Y1  - 2019
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Wurm, Patrick
T1  - Mission analysis and performance comparison for an Advanced Solar Photon Thruster
JF  - Advances in Space Research
Y1  - 2011
SN  - 0273-1177
VL  - 48
IS  - 11
SP  - 1858
EP  - 1868
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Scholz, A.
A1  - Ley, Wilfried
A1  - Dachwald, Bernd
A1  - Miau, J. J.
A1  - Juang, J. C.
T1  - Flight results of the COMPASS-1 picosatellite mission
JF  - Acta Astronautica. 67 (2010), H. 9-10
Y1  - 2010
SN  - 0094-5765
SP  - 1289
EP  - 1298
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  - Korsch, Helge
A1  - Dafnis, Athanasios
A1  - Reimerdes, Hans-Günther
A1  - Braun, Carsten
A1  - Ballmann, Josef
T1  - Dynamic qualification of the HIRENASD elastic wing model
T2  - Motto: Luft- und Raumfahrt: Lehre, Forschung, Industrie - gemeinsam innovativ. Deutscher Luft- und Raumfahrtkongress 2006 : Braunschweig, 06. bis 09. November 2006. Jahrbuch / Deutsche Gesellschaft für Luft- und Raumfahrt. 2006
Y1  - 2006
SP  - 1441
EP  - 1450
PB  - Dt. Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth (DGLR)
CY  - Bonn
ER  - 
TY  - CHAP
A1  - Niedermeier, H.
A1  - Clemens, J.
A1  - Kowalski, Julia
A1  - Macht, S.
A1  - Heinen, D.
A1  - Hoffmann, R.
A1  - Linder, Peter
T1  - Navigation system for a research ice probe for antarctic glaciers
T2  - IEEE/ION Position, Location and Navigation Symposium (PLANS) ; 5-8 May 2014, Monterey, Calif.
Y1  - 2014
SN  - 978-1-4799-3319-8
SP  - 959
EP  - 975
PB  - IEEE
CY  - Piscataway, NJ
ER  - 
TY  - JOUR
A1  - Dahmann, Peter
T1  - Leistungsfähigkeit von Hydraulikfiltern bei unterschiedlichen Betriebsbedingungen
JF  - Ölhydraulik und Pneumatik. 34 (1990), H. 10
Y1  - 1990
SN  - 0341-2660
SP  - 682
EP  - 688
ER  - 
TY  - CHAP
A1  - Seboldt, Wolfgang
A1  - Blome, Hans-Joachim
A1  - Dachwald, Bernd
A1  - Richter, Lutz
T1  - Proposal for an integrated European space exploration strategy
T2  - 55th International Astronautical Congress of the International Astronautical Federation, the International Academy of Astronautics, and the International Institute of Space Law
N2  - Recently, in his vision for space exploration, US president Bush announced to extend human presence across the solar system, starting with a human return to the Moon as early as 2015 in preparation for human exploration of Mars and other destinations. In Europe, an exploration program, termed AURORA, was established by ESA in 2001 – funded on a voluntary basis by ESA member states – with a clear focus on Mars and the ultimate goal of landing humans on Mars around 2030 in international cooperation. In 2003, a Human Spaceflight Vision Group was appointed by ESA with the task to develop a vision for the role of human spaceflight during the next quarter of the century. The resulting vision focused on a European-led lunar exploration initiative as part of a multi-decade, international effort to strengthen European identity and economy. After a review of the situation in Europe concerning space exploration, the paper outlines an approach for a consistent positioning of exploration within the existing European space programs, identifies destinations, and develops corresponding scenarios for an integrated strategy, starting with robotic missions to the Moon, Mars, and near-Earth asteroids. The interests of the European planetary in-situ science community, which recently met at DLR Cologne, are considered. Potential robotic lunar missions comprise polar landings to search for frozen volatiles and a sample return. For Mars, the implementation of a modest robotic landing mission in 2009 to demonstrate the capability for landing and prepare more ambitious and complex missions is discussed. For near-Earth asteroid exploration, a low-cost in-situ technology demonstration mission could yield important results. All proposed scenarios offer excellent science and could therefore create synergies between ESA’s mandatory and optional programs in the area of planetary science and exploration. The paper intents to stimulate the European discussion on space exploration and reflects the personal view of the authors.
Y1  - 2004
N1  - 55th International Astronautical Congress 2004 - Vancouver, Canada
SP  - 1
EP  - 10
ER  - 
TY  - JOUR
A1  - Maiwald, Volker
A1  - Dachwald, Bernd
T1  - Mission Design for a Multiple-Rendezvous Mission to Jupiter's Trojans
Y1  - 2010
N1  - COSPAR 2010 ; 38th COSPAR Scientific Assembly. Held 18-25 July 2010 in Bremen, Germany [Abstract]
SP  - 3
ER  -