TY  - JOUR
A1  - Hoeveler, B.
A1  - Bauknecht, André
A1  - Wolf, C. Christian
A1  - Janser, Frank
T1  - Wind-Tunnel Study of a Wing-Embedded Lifting Fan Remaining Open in Cruise Flight
JF  - Journal of Aircraft
N2  - It is investigated whether a nonrotating lifting fan remaining uncovered during cruise flight, as opposed to being covered by a shutter system, can be realized with limited additional drag and loss of lift during cruise flight. A wind-tunnel study of a wing-embedded lifting fan has been conducted at the Side Wind Test Facility Göttingen of DLR, German Aerospace Center in Göttingen using force, pressure, and stereoscopic particle image velocimetry techniques. The study showed that a step on the lower side of the wing in front of the lifting fan duct increases the lift-to-drag ratio of the whole model by up to 25% for all positive angles of attack. Different sizes and inclinations of the step had limited influence on the surface pressure distribution. The data indicate that these parameters can be optimized to maximize the lift-to-drag ratio. A doubling of the curvature radius of the lifting fan duct inlet lip on the upper side of the wing affected the lift-to-drag ratio by less than 1%. The lifting fan duct inlet curvature can therefore be optimized to maximize the vertical fan thrust of the rotating lifting fan during hovering without affecting the cruise flight performance with a nonrotating fan.
Y1  - 2020
U6  - https://doi.org/10.2514/1.C035422
SN  - 1533-3868
VL  - 57
IS  - 4
PB  - AIAA
CY  - Reston, Va.
ER  - 
TY  - JOUR
A1  - Henn, Gudrun
A1  - Polaczek, Christa
T1  - Studienerfolg in den Ingenieurwissenschaften
JF  - Das Hochschulwesen : HSW ; Forum für Hochschulforschung, -praxis und -politik
Y1  - 2007
SN  - 0018-2974
VL  - 55
IS  - 5
SP  - 144
EP  - 147
ER  - 
TY  - JOUR
A1  - Hein, Andreas M.
A1  - Eubanks, T. Marshall
A1  - Lingam, Manasvi
A1  - Hibberd, Adam
A1  - Fries, Dan
A1  - Schneider, Jean
A1  - Kervella, Pierre
A1  - Kennedy, Robert
A1  - Perakis, Nikolaos
A1  - Dachwald, Bernd
T1  - Interstellar now! Missions to explore nearby interstellar objects
JF  - Advances in Space Research
N2  - The recently discovered first hyperbolic objects passing through the Solar System, 1I/’Oumuamua and 2I/Borisov, have raised the question about near term missions to Interstellar Objects. In situ spacecraft exploration of these objects will allow the direct determination of both their structure and their chemical and isotopic composition, enabling an entirely new way of studying small bodies from outside our solar system. In this paper, we map various Interstellar Object classes to mission types, demonstrating that missions to a range of Interstellar Object classes are feasible, using existing or near-term technology. We describe flyby, rendezvous and sample return missions to interstellar objects, showing various ways to explore these bodies characterizing their surface, dynamics, structure and composition. Their direct exploration will constrain their formation and history, situating them within the dynamical and chemical evolution of the Galaxy. These mission types also provide the opportunity to explore solar system bodies and perform measurements in the far outer solar system.
KW  - Interstellar objects
KW  - Trajectories
KW  - Missions
Y1  - 2022
U6  - https://doi.org/10.1016/j.asr.2021.06.052
SN  - 0273-1177
VL  - 69
IS  - 1
SP  - 402
EP  - 414
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Hein, Andreas M.
A1  - Eubanks, T. Marshall
A1  - Hibberd, Adam
A1  - Fries, Dan
A1  - Schneider, Jean
A1  - Lingam, Manasvi
A1  - Kennedy, Robert
A1  - Perakis, Nikolaos
A1  - Dachwald, Bernd
A1  - Kervella, Pierre
T1  - Interstellar Now! Missions to and sample returns from nearby interstellar objects
N2  - The recently discovered first high velocity hyperbolic objects passing through the Solar System, 1I/'Oumuamua and 2I/Borisov, have raised the question about near term missions to Interstellar Objects. In situ spacecraft exploration of these objects will allow the direct determination of both their structure and their chemical and isotopic composition, enabling an entirely new way of studying small bodies from outside our solar system. In this paper, we map various Interstellar Object classes to mission types, demonstrating that missions to a range of Interstellar Object classes are feasible, using existing or near-term technology. We describe flyby, rendezvous and sample return missions to interstellar objects, showing various ways to explore these bodies characterizing their surface, dynamics, structure and composition. Interstellar objects likely formed very far from the solar system in both time and space; their direct exploration will constrain their formation and history, situating them within the dynamical and chemical evolution of the Galaxy. These mission types also provide the opportunity to explore solar system bodies and perform measurements in the far outer solar system.
Y1  - 2020
SP  - 1
EP  - 8
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Heiligers, Jeannette
A1  - Schoutetens, Frederic
A1  - Dachwald, Bernd
T1  - Photon-sail equilibria in the alpha centauri system
JF  - Journal of Guidance, Control, and Dynamics
Y1  - 2021
U6  - https://doi.org/10.2514/1.G005446
SN  - 1533-3884
SN  - 0731-5090
SN  - 0162-3192
VL  - 44
IS  - 5
SP  - 1053
EP  - 1061
ER  - 
TY  - JOUR
A1  - Heierli, Joachim
A1  - Purves, Ross S.
A1  - Felber, Andreas
A1  - Kowalski, Julia
T1  - Verification of nearest-neighbours interpretations in avalanche forecasting
JF  - Annals of Glaciology
N2  - This paper examines the positive and negative aspects of a range of interpretations of nearest-neighbours models. Measures-oriented and distributionoriented verification methods are applied to categorial, probabilistic and descriptive interpretations of nearest neighbours used operationally in avalanche forecasting in Scotland and Switzerland. The dependence of skill and accuracy measures on base rate is illustrated. The purpose of the forecast and the definition of events are important variables in determining the quality of the forecast. A discussion of the application of different interpretations in operational avalanche forecasting is presented.
KW  - avalanche
Y1  - 2004
SN  - 1727-5644
VL  - 38
IS  - 1
SP  - 84
EP  - 88
ER  - 
TY  - JOUR
A1  - Havermann, Marc
A1  - Seiler, F.
A1  - Georges, A.
A1  - Srulijes, J.
T1  - Progress in Doppler picture velocimetry (DPV) / Seiler, F. ; George, A. ; Srulijes, J. ; Havermann, M.
JF  - Experiments in Fluids. 44 (2008), H. 3
Y1  - 2008
SN  - 1432-1114
SP  - 389
EP  - 395
PB  - -
ER  - 
TY  - JOUR
A1  - Havermann, Marc
A1  - Seiler, F.
A1  - Georges, A.
A1  - Leopold, F.
T1  - Das Dopplerbildverfahren (DPV) des ISL zur Messung der Strömungsgeschwindigkeit in einer Ebene / Seiler, F. ; Georges, A. ; Leopold, F. ; Srulijes, J. ; Havermann, M.
JF  - Lasermethoden in der Strömungsmesstechnik, 10. Fachtagung, Deutsche Gesellschaft für Laser-Anemometrie GALA, Rostock, DE, 10.-12. Sep, 2002
Y1  - 2002
SN  - 3-86009-233-2
SP  - 11.1
EP  - 11.6
PB  - Univ.
CY  - Rostock
ER  - 
TY  - JOUR
A1  - Havermann, Marc
A1  - Seiler, F.
A1  - George, A.
A1  - Leopold, F.
T1  - Planar Velocity Visualization in High-Speed Wedge Flow using Doppler Picture Velocimetry (DPV) compared with Particle Image Velocimetry (PIV) / Seiler, F. ; Havermann, M. ; George, A. ; Leopold, F. ; Srulijes, J.
JF  - Journal of Visualization. 6 (2003), H. 3
Y1  - 2003
SN  - 1343-8875
SP  - 253
EP  - 262
PB  - -
ER  - 
TY  - JOUR
A1  - Havermann, Marc
A1  - Seiler, F.
A1  - George, A.
A1  - Leopold, F.
T1  - Enhanced Doppler Picture Velocimetry (DPV) for Planar Velocity Measurements in High-Speed Shock Tunnel Flow / Seiler, F. ; George, A. ; Leopold, F. ; Havermann, M. ; Srulijes, J.
JF  - 10th International Symposium on Flow Visualization : Kyōto, Japan, August 26 - 29, 2002 / sponsored by International Flow Visualization Society . [Chairman:] Toshio Kobayashi
Y1  - 2002
SN  - 4906497829
N1  - International Symposium on Flow Visualization ; (10 ; 2002.08.26-29 ; Kyōto)
PB  - Visualization Society of Japan
CY  - Kyoto
ER  -