TY  - JOUR
A1  - Dachwald, Bernd
T1  - Optimal Solar Sail Trajectories for Missions to the Outer Solar System
JF  - 22nd AIAA Applied Aerodynamics Conference and Exhibit - AIAA/AAS Astrodynamics Specialist Conference and Exhibit - AIAA Guidance, Navigation, and Control Conference and Exhibit - AIAA Modeling and Simulation Technologies Conference and Exhibit - AIAA Atmospheric Flight Mechanics Conference and Exhibit : 16 - 19 August 2004, Providence, Rhode Island / American Institute of Aeronautics and Astronautics. - (AIAA meeting papers on disc ; 2004,14-15)
Y1  - 2004
N1  - American Institute of Aeronautics and Astronautics <Reston, Va.> ; AIAA/AAS Astrodynamics Specialist Conference and Exhibit <2004, Providence, RI> ; AIAA paper number: AIAA-2004-5406
PB  - American Inst. of Aeronautics and Astronautics
CY  - Reston, Va.
ER  - 
TY  - BOOK
A1  - Havermann, Marc
A1  - Seiler, Friedrich
T1  - Boundary layer influence on supersonic jet cross flow interaction in hypersonic flow : DGLR/STAB-Fachsymposium Strömungsmechanik 2004, Bremer Innovations- und Technologiezentrum (BITZ), Bremen, FRG, 16. - 18. November 2004 / Havermann, M.; Seiler, F. Institut Franco-Allemand de Recherches de Saint-Louis
Y1  - 2004
N1  - Publication / Institut Franco-Allemand de Recherches de Saint-Louis ; 658
PB  - ISL
CY  - Saint-Louis
ER  - 
TY  - BOOK
A1  - Havermann, Marc
T1  - Shock tunnel measurement of the interaction amplification factor for a hot gas side jet in a supersonic cross-flow : 24th International Symposium on Shock Waves, Beijing, China, July 11 - 16, 2004 / Institut Franco-Allemand de Recherches de Saint-Louis. Havermann, M. ...
Y1  - 2004
N1  - Publication / Institut Franco-Allemand de Recherches de Saint-Louis ; 642
PB  - ISL
CY  - Saint-Louis
ER  - 
TY  - BOOK
A1  - Havermann, Marc
A1  - Seiler, F.
A1  - George, A.
A1  - Srulijes, J.
T1  - Doppler Picture Velovimetry (DPV) applied to high speed shock tunnel flows : 11th International Symposium on Flow Visualization, University of Notre Dame, Notre Dame/IN, USA, August 9 - 12, 2004 / Institut Franco-Allemand de Recherches de Saint-Louis. Seiler, F. ...
Y1  - 2004
PB  - ISL
CY  - Saint-Louis
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  - 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  - CHAP
A1  - Dachwald, Bernd
T1  - Solar sail performance requirements for missions to the outer solar system and beyond
T2  - 55th International Astronautical Congress 2004
N2  - Solar sails enable missions to the outer solar system and beyond, although the solar
radiation pressure decreases with the square of solar distance. For such missions, the solar sail may gain a large amount of energy by first making one or more close approaches to the sun. Within this paper, optimal trajectories for solar sail missions to the outer planets and into near interstellar space (200 AU) are presented. Thereby, it is shown that even near/medium-term solar sails with relatively moderate performance allow reasonable transfer times to the boundaries of the solar system.
Y1  - 2004
U6  - http://dx.doi.org/10.2514/6.IAC-04-S.P.11
N1  - 55th International Astronautical Congress 2004 - Vancouver, Canada
SP  - 1
EP  - 9
ER  - 
TY  - JOUR
A1  - Blome, Hans-Joachim
A1  - Wilson, Thomas L.
T1  - The quantum temperature of accelerating cosmological models of an entangled Universe
JF  - Advances in Space Research. 35 (2005), H. 1
Y1  - 2005
SN  - 0273-1177
SP  - 111
EP  - 115
ER  - 
TY  - JOUR
A1  - Blome, Hans-Joachim
A1  - Kosbow, Michael
T1  - The Pioneer Anomaly in the context of non-Newtonian Gravity
JF  - International Astronautical Congress : final papers : October 17-21, 2005, Fukuoka, Japan
Y1  - 2005
N1  - Proceedings IAC-2005-C1.P.20 ;International Astronautical Congress ; (56, 2005, Fukuoka, Japan)
SP  - 20
EP  - 20
PB  - International Astronautical Federation
CY  - Paris
ER  - 
TY  - JOUR
A1  - Czupalla, Markus
A1  - Horneck, G.
A1  - Blome, Hans-Joachim
T1  - The conceptual design of a hybrid life support system based on the evaluation and comparison of terrestrial testbeds
JF  - Advances in Space Research
Y1  - 2005
SN  - 0273-1177
VL  - 35
IS  - 9
SP  - 1609
EP  - 1620
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Seboldt, W.
T1  - Multiple Near-Earth Asteroid Rendezvous and Sample Return Using First Generation Solar Sailcraft
JF  - Acta Astronautica. 57 (2005), H. 11
Y1  - 2005
SN  - 0094-5765
SP  - 864
EP  - 875
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
T1  - Optimization of very-low-thrust trajectories using evolutionary neurocontrol
JF  - Acta Astronautica. 57 (2005), H. 2-8
Y1  - 2005
SN  - 0094-5765
SP  - 175
EP  - 185
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
T1  - Optimal Solar Sail Trajectories for Missions to the Outer Solar System
JF  - Journal of guidance, control, and dynamics. 28 (2005), H. 6
Y1  - 2005
SN  - 0162-3192
N1  - 2. ISSN: 0162-3192. - 3. ISSN: 0731-5090
SP  - 1187
EP  - 1193
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Seboldt, Wolfgang
A1  - Macdonald, Malcolm
A1  - Mengali, Giovanni
A1  - Quatra, Alessandro A.
A1  - McInnes, Colin R.
A1  - Rios-Reyes, Leonel
A1  - Scheerers, Daniel J.
A1  - Wie, Bong
A1  - Görlich, Marianne
A1  - Lura, Franz
A1  - Diedrich, Benjamin
A1  - Baturkin, Volodymyr
A1  - Coverstone, Victoria L.
A1  - Leipold, Manfred
A1  - Garbe, Gregory P.
T1  - Potential Solar Sail Degradation Effects on Trajectory and Attitude Control
JF  - AIAA Guidance, Navigation and Control Conference and Exhibit - AIAA Modeling and Simulation Technologies Conference and Exhibit - AIAA Atmospheric Flight Mechanics Conference and Exhibit : [San Francisco, California, 15 - 18 August 2005 ; papers]. - (AIAA meeting papers on disc ; [10.]2005,16-17)
Y1  - 2005
SN  - 1-56347-765-3
N1  - American Institute of Aeronautics and Astronautics <Reston, Va.> ; AIAA Guidance, Navigation, and Control Conference and Exhibit <2005, San Francisco, Calif.> ; AIAA paper number: AIAA-2006-6172
Link "<a href="https://arc.aiaa.org/doi/book/10.2514/MGNC05"_blank">https://arc.aiaa.org/doi/book/10.2514/MGNC05</a>" am 15.07.2022 nachgetragen Behr
PB  - American Institute of Aeronautics and Astronautics
CY  - Reston, Va.
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Wie, Bong
T1  - Solar Sail Trajectory Optimization for Intercepting, Impacting, and Deflecting Near-Earth Asteroids
JF  - AIAA Guidance, Navigation and Control Conference and Exhibit - AIAA Modeling and Simulation Technologies Conference and Exhibit - AIAA Atmospheric Flight Mechanics Conference and Exhibit : [San Francisco, California, 15 - 18 August 2005 ; papers]. - (AIAA meeting papers on disc ; [10.]2005,16-17)
Y1  - 2005
SN  - 1-56347-765-3
N1  - American Institute of Aeronautics and Astronautics <Reston, Va.> ; AIAA Guidance, Navigation, and Control Conference and Exhibit <2005, San Francisco, Calif.> ; AIAA paper number: AIAA-2006-6176
PB  - American Institute of Aeronautics and Astronautics
CY  - Reston, Va.
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Seboldt, W.
T1  - Solar Sails for Near- and Medium-Term Scientific Deep Space Missions / W. Sebolt ; B. Dachwald
JF  - In-space propulsion : edited book of proceedings of the 10-IWCP, the 10th International Workshop on Combustion and Propulsion held in Lerici, La Spezia, Italy, 21-25 September 2003 / [ed.: Luigi T. DeLuca]
Y1  - 2005
N1  - Paper 31 ; International workshop on combustion and propulsion <10, 2003, Lerici>
PB  - SP Lab, Politecnico di Milano
CY  - Milano
ER  - 
TY  - JOUR
A1  - Dittus, H.
A1  - Turyshev, S. G.
A1  - Dachwald, Bernd
A1  - Blome, Hans-Joachim
T1  - A Mission to Explore the Pioneer Anomaly
JF  - Proceedings of the 39th ESLAB Symposium "Trends in Space Science and Cosmic Vision 2020" : 19 - 21 April 2005, ESTEC, Noordwijk, the Netherlands / European Space Agency. [Comp. by: F. Favata ...] . - (ESA SP ; 588)
Y1  - 2005
SN  - 9290928999
N1  - ISBN der CD-ROM-Ausg.: 9290928999 ; Symposium Trends in Space Science and Cosmic Vision 2020 <2005, Noordwijk> ; ESLAB symposium <39,2005, Noordwijk> ; European Space Laboratory ; Report Number: LA-UR-05-4907 ; The Pioneer Explorer Collaboration
SP  - 3
EP  - 10
PB  - ESA Publ. Div.
CY  - Noordwijk
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Turyshev, Slava G.
A1  - Dittus, H.
A1  - Shao, M. [u.a.]
T1  - Fundamental Physics with the Laser Astrometric Test Of Relativity / S.G. Turyshev ;  H. Dittus ; M. Shao ... B.Dachwald ...
JF  - Proceedings of the 39th ESLAB Symposium "Trends in Space Science and Cosmic Vision 2020" : 19 - 21 April 2005, ESTEC, Noordwijk, the Netherlands / European Space Agency. [Comp. by: F. Favata ...] . - (ESA SP ; 588)
Y1  - 2005
SN  - 9290928999
N1  - ISBN der CD-ROM-Ausg.: 9290928999 ; Symposium Trends in Space Science and Cosmic Vision 2020 <2005, Noordwijk> ; ESLAB symposium <39, 2005, Noordwijk> ; European Space Laboratory
SP  - 8
EP  - 11
PB  - ESA Publ. Div.
CY  - Noordwijk
ER  - 
TY  - JOUR
A1  - Gerhardt, Hans Joachim
T1  - Design methods of smoke and heat exhaust systems in construction works
JF  - V Mie&#796;dzynarodowa Konferencja Bezpiecze&#324;stwo Po&#380;arowe Budowli, Warszawa-Miedzeszyn, 14 - 16 listopada 2005 r. = : Vth International Conference Fire Safety of Buildings / ITB ... [Ed. Miros&#322;aw Kosiorek]
Y1  - 2005
SN  - 83-7413-810-6
N1  - Mie&#796;dzynarodowa Konferencja Bezpiecze&#324;stwo Po&#380;arowe Budowli <5, 2005, Warszawa> ; International Conference Fire Safety of Buildings <5, 2005, Warszawa-Miedzeszyn>
SP  - 127
EP  - 140
PB  - ITB
CY  - Warszawa
ER  - 
TY  - JOUR
A1  - Gerhardt, Hans Joachim
A1  - Konrath, B.
A1  - Lieb, R.-D.
T1  - Das Drallrohr
JF  - HLH : Lüftung, Klima, Heizung, Sanitär, Gebäudetechnik. 56 (2005), H. 11
Y1  - 2005
SN  - 1436-5103
N1  - 2. ISSN: 0017-9906 ; 3. ISSN: 1434-422X ; Zeitschrift unter 13 Z 739 in der Bibliothek
SP  - 91
EP  - 95
ER  - 
TY  - JOUR
A1  - Havermann, Marc
T1  - Effects of the shock tube open-end shape on vortex loops released from it / Kainuma, M. ; Havermann, M. ; Sun, M. ; Takayama, K.
JF  - Shock Waves : Proceedings of the 24th International Symposium on Shock Waves Beijing, China July 11-16, 2004 / edited by Z. Jiang
Y1  - 2005
SN  - 978-3-540-22497-6
SP  - 505
EP  - 510
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Havermann, Marc
A1  - Seiler, F.
A1  - Boller, F.
A1  - Mangold, P.
T1  - Operation of the ISL transonic shock tube in a high subsonic flow regime / Seiler, F. ; Havermann, M. ; Boller, F. ; Mangold, P. ; Takayama K.
JF  - Shock Waves : Proceedings of the 24th International Symposium on Shock Waves Beijing, China July 11-16, 2004 / edited by Z. Jiang
Y1  - 2005
SN  - 978-3-540-22497-6
SP  - 307
EP  - 312
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Havermann, Marc
A1  - Ende, H.
A1  - Seiler, F.
A1  - Schwenzer, M.
T1  - Shock tunnel measurement of the interaction amplification factor for a hot gas side jet in a supersonic cross flow / Havermann, M. ; Ende, H. ; Seiler, F. ; Schwenzer, M.
JF  - Shock Waves : Proceedings of the 24th International Symposium on Shock Waves Beijing, China July 11-16, 2004 / edited by Z. Jiang
Y1  - 2005
SN  - 978-3-540-22497-6
SP  - 113
EP  - 118
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Havermann, Marc
A1  - Kainuma, M.
A1  - Takayama, K.
T1  - Influence of Physical and Geometrical Parameters on Vortex Rings Generated by a Shock Tube / Havermann, M. ; Kainuma, M. ; Takayama, K.
JF  - Non-lethal options enhancing security and stability : 3rd European Symposium on Non-Lethal Weapons, May 10 - 12, 2005, Ettlingen, Germany / ICT, Fraunhofer-Institut Chemische Technologie; European Working Group Non-Lethal Weapons
Y1  - 2005
N1  - European Symposium on Non-Lethal Weapons ; (3 ; 2005.5.10-12 ; Ettlingen); V 24
PB  - ICT
CY  - Pfinztal
ER  - 
TY  - JOUR
A1  - Havermann, Marc
A1  - Moeglin, J.-P.
T1  - ISL's Research on Systems with Controlled Effects for Non-Lethal Applications / Moeglin, J.-P. ; Havermann, M. et al.
JF  - Non-lethal options enhancing security and stability : 3rd European Symposium on Non-Lethal Weapons, May 10 - 12, 2005, Ettlingen, Germany / ICT, Fraunhofer-Institut Chemische Technologie; European Working Group Non-Lethal Weapons
Y1  - 2005
N1  - European Symposium on Non-Lethal Weapons ; (3 ; 2005.5.10-12 ; Ettlingen); P 35
PB  - ICT
CY  - Pfinztal
ER  - 
TY  - BOOK
A1  - Havermann, Marc
T1  - Development of a free flight force measuring (FFM) technique at the ISL shock tube laboratory : 25th International Symposium on Shock Waves, ISSW25, Bangalore, India, July 17 - 22, 2005 / Institut Franco-Allemand de Recherches de Saint-Louis. Seiler, F. ; Mathieu, G. ;  George,  A. ; Srulijes, J. ; Sauerwein, B. ; Havermann, M.
Y1  - 2005
N1  - Publication / Institut Franco-Allemand de Recherches de Saint-Louis ; 620
PB  - ISL
CY  - Saint-Louis
ER  - 
TY  - CHAP
A1  - Braun, Carsten
A1  - Boucke, Alexander
A1  - Ballmann, Josef
T1  - Numerical prediction of the wing deformation of a high speed transport aircraft type wind tunnel model by direct aeroelastic simulation
T2  - Conference proceedings : CEAS/AIAA/DGLR International Forum on Aeroelasticity and Structural Dynamics IFASD 2005 : München, June 28 - July 1, 2005. DGLR-Bericht. 2005,04
Y1  - 2005
SN  - 3-932182-43-X
PB  - DGLR
CY  - Bonn
ER  - 
TY  - CHAP
A1  - Braun, Carsten
A1  - Boucke, Alexander
A1  - Ballmann, Josef
T1  - Numerical study of the influence of dynamic pressure and deflected ailerons on the deformation of a high speed wing model
T2  - High performance computing in science and engineering '04. Transactions of the High Performance Computing Center Stuttgart (HLRS) 2004 /  Eds.: Egon Krause ...
Y1  - 2005
SN  - 3-540-22943-4
SP  - 225
EP  - 236
PB  - Springer
CY  - Berlin
ER  - 
TY  - CHAP
A1  - Plescher, Engelbert
A1  - Mathiak, Gerhard
A1  - Willnecker, Rainer
T1  - Technical aspects of liquid diffusion model experiments
T2  - 55th International Astronautical Congress : October 4 - 8, 2004, Vancouver, Canada / International Astronautical Federation. Bd. 8. IAC-04-J.5.04
Y1  - 2005
SP  - 5019
EP  - 5025
PB  - International Astronautical Federation
CY  - Paris
ER  - 
TY  - JOUR
A1  - Mathiak, Gerhard
A1  - Plescher, Engelbert
A1  - Willnecker, Rainer
T1  - Liquid metal diffusion experiments in microgravity - Vibrational effects
JF  - Measurement science and technology
Y1  - 2005
U6  - http://dx.doi.org/10.1088/0957-0233/16/2/003
SN  - 0957-0233
VL  - Vol. 16
IS  - No. 2
SP  - 336
ER  - 
TY  - JOUR
A1  - Mathiak, Gerhard
A1  - Willnecker, Rainer
A1  - Plescher, Engelbert
T1  - Vibrational effects on diffusion experiments
JF  - Microgravity science and technology : international journal for microgravity research and applications
Y1  - 2005
SN  - 0938-0108
VL  - Vol. 15
IS  - No. 1
SP  - 295
EP  - 300
ER  - 
TY  - CHAP
A1  - Dachwald, Bernd
T1  - Global optimization of low-thrust space missions using evolutionary neurocontrol
T2  - Proceedings of the international workshop on global optimization
N2  - Low-thrust space propulsion systems enable flexible high-energy deep space missions, but the design and optimization of the interplanetary transfer trajectory is usually difficult. It involves much experience and expert knowledge because the convergence behavior of traditional local trajectory optimization methods depends strongly on an adequate initial guess. Within this extended abstract, evolutionary neurocontrol, a method that fuses artificial neural networks and evolutionary algorithms, is proposed as a smart global method for low-thrust trajectory optimization. It does not require an initial guess. The implementation of evolutionary neurocontrol is detailed and its performance is shown for an exemplary mission.
KW  - Evolutionary Neurocontrol
KW  - Spacecraft Trajectory Optimization
KW  - Low-Thrust Propulsion
Y1  - 2005
SP  - 85
EP  - 90
ER  - 
TY  - CHAP
A1  - Dachwald, Bernd
A1  - Baturkin, Volodymyr
A1  - Coverstone, Victoria
A1  - Diedrich, Ben
A1  - Garbe, Gregory
A1  - Görlich, Marianne
A1  - Leipold, Manfred
A1  - Lura, Franz
A1  - Macdonald, Malcolm
A1  - McInnes, Colin
A1  - Mengali, Giovanni
A1  - Quarta, Alessandro
A1  - Rios-Reyes, Leonel
A1  - Scheeres, Daniel J.
A1  - Seboldt, Wolfgang
A1  - Wie, Bong
T1  - Potential effects of optical solar sail degredation on trajectory design
T2  - AAS/AIAA Astrodynamics Specialist
N2  - The optical properties of the thin metalized polymer films that are projected for solar sails are assumed to be affected by the erosive effects of the space environment. Their degradation behavior in the real space environment, however, is to a considerable degree indefinite, because initial ground test results are controversial and relevant inspace tests have not been made so far. The standard optical solar sail models that are currently used for trajectory design do not take optical degradation into account, hence its potential effects on trajectory design have not been investigated so far. Nevertheless, optical degradation is important for high-fidelity solar sail mission design, because it decreases both the magnitude of the solar radiation pressure force acting on the sail and also the sail control authority. Therefore, we propose a simple parametric optical solar sail degradation model that describes the variation of the sail film’s optical coefficients with time, depending on the sail film’s environmental history, i.e., the radiation dose. The primary intention of our model is not to describe the exact behavior of specific film-coating combinations in the real space environment, but to provide a more general parametric framework for describing the general optical degradation behavior of solar sails. Using our model, the effects of different optical degradation behaviors on trajectory design are investigated for various exemplary missions.
Y1  - 2005
N1  - 2005 AAS/AIAA Astrodynamics Specialist Conference, 7-11.08.2005. Lake Tahoe, California
https://www.space-flight.org/AAS_meetings/2005_astro/2005_astro.html
SP  - 1
EP  - 23
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
T1  - Optimization of very-low-thrust trajectories using evolutionary neurocontrol
JF  - Acta Astronautica
N2  - Searching optimal interplanetary trajectories for low-thrust spacecraft is usually a difficult and time-consuming task that involves much experience and expert knowledge in astrodynamics and optimal control theory. This is because the convergence behavior of traditional local optimizers, which are based on numerical optimal control methods, depends on an adequate initial guess, which is often hard to find, especially for very-low-thrust trajectories that necessitate many revolutions around the sun. The obtained solutions are typically close to the initial guess that is rarely close to the (unknown) global optimum. Within this paper, trajectory optimization problems are attacked from the perspective of artificial intelligence and machine learning. Inspired by natural archetypes, a smart global method for low-thrust trajectory optimization is proposed that fuses artificial neural networks and evolutionary algorithms into so-called evolutionary neurocontrollers. This novel method runs without an initial guess and does not require the attendance of an expert in astrodynamics and optimal control theory. This paper details how evolutionary neurocontrol works and how it could be implemented. The performance of the method is assessed for three different interplanetary missions with a thrust to mass ratio <0.15mN/kg (solar sail and nuclear electric).
Y1  - 2005
SN  - 1879-2030
VL  - 57
IS  - 2-8
SP  - 175
EP  - 185
PB  - Elsevier
CY  - Amsterdam [u.a.]
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Seboldt, W.
A1  - Richter, L.
T1  - Multiple rendezvous and sample return missions to near-Earth objects using solar sailcraft / Dachwald, B. ; Seboldt, W. ; Richter, L.
JF  - Acta Astronautica. 59 (2006), H. 8-11
Y1  - 2006
SN  - 0094-5765
N1  - International Conference on Low Cost Planetary Missions <5, 2003, Noordwijk> ; Selected Proceedings
SP  - 768
EP  - 776
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Mengali, Giovanni
A1  - Quarta, Alessandrao A.
A1  - Macdonald, Malcolm
T1  - Parametric Model and Optimal Control of Solar Sails with Optical Degradation
JF  - Journal of guidance, control, and dynamics. 29 (2006), H. 5
Y1  - 2006
SN  - 0162-3192
N1  - 2. ISSN: 0731-5090
SP  - 1170
EP  - 1178
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Kahle, Ralph
A1  - Wie, Bong
T1  - Solar Sailing Kinetic Energy Impactor (KEI) Mission Design Tradeoffs for Impacting and Deflecting Asteroid 99942 Apophis
JF  - AIAA Guidance, Navigation, and Control Conference & Exhibit - AIAA Atmospheric Flight Mechanics Conference & Exhibit - AIAA Modeling and Simulation Technologies Conference & Exhibit - AIAA/AAS Astrodynamics Specialist Conference & Exhibit : [21 - 24 August 2006, Keystone, Colorado ; papers]. - (AIAA meeting papers on disc ; [11.]2006,19-20 )
Y1  - 2006
SN  - 1-56347-802-1
N1  - American Institute of Aeronautics and Astronautics <Reston, Va.> ; American Astronautical Society ; AIAA/AAS Astrodynamics Specialist Conference & Exhibit <2006,  Keystone, Colo.> ; AIAA paper number: AIAA-2006-6178
SP  - 1
EP  - 20
PB  - American Institute of Aeronautics and Astronautics
CY  - Reston, Va.
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Ohndorf, A.
A1  - Wie, Bong
T1  - Solar Sail Trajectory Optimization for the Solar Polar Imager (SPI) Mission
JF  - AIAA Guidance, Navigation, and Control Conference & Exhibit - AIAA Atmospheric Flight Mechanics Conference & Exhibit - AIAA Modeling and Simulation Technologies Conference & Exhibit - AIAA/AAS Astrodynamics Specialist Conference & Exhibit : [21 - 24 August 2006, Keystone, Colorado ; papers]. - (AIAA meeting papers on disc ; [11.]2006,19-20 )
Y1  - 2006
SN  - 1-56347-802-1
N1  - American Institute of Aeronautics and Astronautics <Reston, Va.> ; American Astronautical Society ; AIAA/AAS Astrodynamics Specialist Conference & Exhibit <2006,  Keystone, Colo.> ; AIAA paper number: AIAA-2006-6177
PB  - American Institute of Aeronautics and Astronautics
CY  - Reston, Va.
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Carnelli, I.
A1  - Vasile, M.
T1  - Low-Thrust Gravity Assist Trajectory Optimization Using Evolutionary Neurocontrollers / I. Carnelli ; B. Dachwald ; M. Vasile ...
JF  - Astrodynamics 2005 : proceedings of the AAS/AIAA astrodynamics conference held August 7 - 11, 2005, South Lake Tahoe, California / ed. by Bobby G. Williams. - Pt. 3. - (Advances in the astronautical sciences ; 123,3)
Y1  - 2006
SN  - 0-87703-527-X
N1  - Astrodynamics Conference <2005, South Lake Tahoe, Calif.> ; American Astronautical Society ; Number: AAS-05-374
SP  - 1911
EP  - 1928
PB  - Univelt
CY  - San Diego, Calif.
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Baturkin, Volodymyr
A1  - Coverstone, Victoria L.
A1  - Dietrich, Benjamin
A1  - Garbe, Gregory P.
A1  - Görlich, Marianne
A1  - Leipold, Manfred
A1  - Lura, Franz
A1  - Macdonald, Malcolm
A1  - McInnes, Colin R.
A1  - Mengali, Giovanni
A1  - Quatra, Alessandro A.
A1  - Rios-Reyes, Leonel
A1  - Scheeres, Daniel J.
A1  - Seboldt, Wolfgang
A1  - Wie, Bong
T1  - Potential Effects of Optical Solar Sail Degradation on Interplanetary Trajectory Design
JF  - Astrodynamics 2005 : proceedings of the AAS/AIAA astrodynamics conference held August 7 - 11, 2005, South Lake Tahoe, California / ed. by Bobby G. Williams. - Pt. 3. - (Advances in the astronautical sciences ; 123,3)
Y1  - 2006
UR  - http://www.spacesailing.net/paper/200508_LakeTahoe_Dachwald+.pdf
SN  - 0-87703-527-X
N1  - Astrodynamics Conference <2005, South Lake Tahoe, Calif.> ; American Astronautical Society ; Number: AAS-05-413
SP  - 2569
EP  - 2592
PB  - Univelt
CY  - San Diego, Calif.
ER  - 
TY  - JOUR
A1  - Leipold, M.
A1  - Fichtner, H.
A1  - Heber, B.
A1  - Groepper, P.
A1  - Lascar, S.
A1  - Burger, F.
A1  - Eiden, M.
A1  - Niederstadt, T.
A1  - Sickinger, C.
A1  - Herbeck, L.
A1  - Dachwald, Bernd
A1  - Seboldt, W.
T1  - Heliopause Explorer - A Sailcraft Mission to the Outer Boundaries of the Solar System
JF  - Acta Astronautica. 59 (2006), H. 8-11
Y1  - 2006
SN  - 0094-5765
N1  - International Conference on Low Cost Planetary Missions <5, 2003, Noordwijk> ; Selected Proceedings
SP  - 786
EP  - 796
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Carnelli, I.
A1  - Vasile, M.
T1  - Evolutionary Neurocontrol as a Novel Method for Low-Thrust Gravity Assist Trajectory Optimization / I. Carnelli ; B. Dachwald ; M. Vasile
JF  - Proceedings of the Twenty-Fifth International Symposium on Space Technology and Science (Selected papers) : Kanazawa, [June 4 through June 11, 2006, at Kanazawa-shi Kanko Kaikan in Kanazawa city] / [Japan Society for Aeronautical and Space Sciences. Kohtaro Matsumoto [ed.-in-chief]
Y1  - 2006
SN  - 4-99005-002-9
N1  - International Symposium on Space Technology and Science <25, 2006, Kanazawa> ; ISTS 2006-d-46
SP  - 569
EP  - 574
PB  - JSASS
CY  - Tokyo
ER  - 
TY  - BOOK
A1  - Havermann, Marc
T1  - PIV measurements in shock tunnels : PivNet 2, Final Workshop, Göttingen, 07. - 08.09.2006
Y1  - 2006
N1  - Publication / Institut Franco-Allemand de Recherches de Saint Louis ; 644
PB  - ISL
CY  - Saint-Louis
ER  - 
TY  - BOOK
A1  - Havermann, Marc
T1  - PIV measurements of compressible vortex rings generated by a shock tube : 13th International Symposium on Applications of Laser Techniques to Fluid Mechanics, Lisbon, PT, 26-29.06.2006; axe de recherches 2.14 / Haertig, J.; Rey, C.; Havermann, M. Institut Franco-Allemand de Recherches de Saint-Louis
Y1  - 2006
N1  - Publication / Institut Franco-Allemand de Recherches de Saint Louis ; 645
PB  - ISL
CY  - Saint-Louis
ER  - 
TY  - JOUR
A1  - Havermann, Marc
A1  - Seiler, F.
T1  - Boundary Layer Influence on Supersonic Jet/Cross-Flow Interaction in Hypersonic Flow / Havermann, M. ; Seiler, F.
JF  - Notes on Numerical Fluid Mechanics and Multidisciplinary Design. 92 (2006)
Y1  - 2006
SN  - 1612-2909
N1  - New results in numerical and experimental fluid mechanics ; V ;
ISBN 978-3-540-33287-9
SP  - 281
EP  - 288
PB  - -
ER  - 
TY  - BOOK
A1  - Havermann, Marc
A1  - Seiler, F.
A1  - George, A.
A1  - Srulijes, J.
T1  - Progress in doppler picture velocimetry (DPV) technique : 12th International Symposium on Flow Visualization, DLR, Göttingen, September 10 - 14, 2006 / Institut Franco-Allemand de Recherches de Saint-Louis. Seiler, F. ...
Y1  - 2006
N1  - Publication / Institut Franco-Allemand de Recherches de Saint Louis ; 624
PB  - ISL
CY  - Saint-Louis
ER  - 
TY  - JOUR
A1  - Havermann, Marc
T1  - Systematic Shock Tube Experiments on Vortex Ring Generation and Propagation / Havermann, M. ; Kainuma, M. ; Takayama, K.
JF  - Shock waves : proceedings of the 25th International Symposium on Shock Waves-ISSW25, July 17 - 22, 2005, Bangalore, India / ed.: G. Jagadeesh
Y1  - 2006
SN  - 978-81-7371571-6
N1  - International Symposium on Shock Waves ; 25 (Bangalore) : 2005.07.17-22
ISSW ; 25 (Bangalore) : 2005.07.17-22
PB  - Universities Pr.
CY  - Hyderabad
ER  - 
TY  - CHAP
A1  - Kowalski, Julia
T1  - Numerical Debris Flow Simulation
T2  - Schweizer Numerik Kolloquium : Book of Abstracts 12. April 2006
Y1  - 2006
ER  - 
TY  - CHAP
A1  - Kowalski, Julia
A1  - McArdell, B. W.
A1  - Bartelt, Perry
T1  - A comparison of two approaches to modeling multiphase gravity currents
T2  - Geophysical Research Abstracts
Y1  - 2006
N1  - A-08738
VL  - 8
ER  - 
TY  - CHAP
A1  - Reimer, Lars
A1  - Braun, Carsten
A1  - Ballmann, Josef
T1  - Analysis of the static and dynamic aero-structural response of an elastic swept wing model by direct aeroelastic simulation
T2  - ICAS 2006 proceedings : 25th Congress of the International Council of the Aeronautical Sciences ; Hamburg, Germany, 3 - 8 September, 2006 : 25th International Congress of Aeronautical Sciences
Y1  - 2006
SN  - 0-9533991-7-6
SP  - Paper No. 2006-10.3.3
PB  - Optimage
CY  - Edinburgh
ER  - 
TY  - CHAP
A1  - Ballmann, Josef
A1  - Dafnis, Athanasios
A1  - Braun, Carsten
A1  - Korsch, Helge
A1  - Reimerdes, Hans-Günther
A1  - Braun, Carsten
A1  - Ballmann, Josef
T1  - The HIRENASD project: High Reynolds number aerostructural dynamics experiments in the European Transonic Wind Tunnel (ETW)
T2  - ICAS 2006 proceedings : 25th Congress of the International Council of the Aeronautical Sciences ; Hamburg, Germany, 3 - 8 September, 2006 : 25th International Congress of Aeronautical Sciences
Y1  - 2006
SN  - 0-9533991-7-6
SP  - Paper No. 2006-5.11.2
PB  - Optimage
CY  - Edinburgh
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  - Loeb, Horst W.
A1  - Schartner, Karl-Heinz
A1  - Seboldt, Wolfgang
A1  - Dachwald, Bernd
A1  - Streppel, Joern
A1  - Meusemann, Hans
A1  - Schülke, Peter
T1  - SEP for a lander mission to the jovian moon europa
T2  - 57th International Astronautical Congress
N2  - Under DLR-contract, Giessen University and DLR Cologne are studying solar-electric propulsion missions (SEP) to the outer regions of the solar system. The most challenging reference mission concerns the transport of a 1.35-tons chemical lander spacecraft into an 80-RJ circular orbit around Jupiter, which would enable to place a 375 kg lander with 50 kg of scientific instruments on the surface of the icy moon "Europa". Thorough analyses show that the best solution in terms of SEP launch mass times thrusting time would be a two-stage EP module and a triple-junction solar array with concentrators which would be deployed step by step. Mission performance optimizations suggest to propel the spacecraft in the first EP stage by 6 gridded ion thrusters, running at 4.0 kV of beam voltage, which would save launch mass, and in the second stage by 4 thrusters with 1.25 to 1.5 kV of positive high voltage saving thrusting time. In this way, the launch mass of the spacecraft would be kept within 5.3 tons. Without a launcher's C3 and interplanetary gravity assists, Jupiter might be reached within about 4 yrs. The spiraling-down into the parking orbit would need another 1.8 yrs. This "large mission" can be scaled down to a smaller one, e.g., by halving all masses, the solar array power, and the number of thrusters. Due to their reliability, long lifetime and easy control, RIT-22 engines have been chosen for mission analysis. Based on precise tests, the thruster performance has been modeled.
Y1  - 2006
U6  - http://dx.doi.org/10.2514/6.IAC-06-C4.4.04
N1  - 57th International Astronautical Congress, 02 October 2006 - 06 October 2006, Valencia, Spain.
SP  - 1
EP  - 12
ER  - 
TY  - CHAP
A1  - Dachwald, Bernd
A1  - Kahle, Ralph
A1  - Wie, Bong
T1  - Solar sail Kinetic Energy Impactor (KEI) mission design tradeoffs for impacting and deflecting asteroid 99942 Apophis
T2  - AIAA/AAS Astrodynamics Specialist Conference and Exhibit
N2  - Near-Earth asteroid 99942 Apophis provides a typical example for the evolution of asteroid orbits that lead to Earth-impacts after a close Earth-encounter that results in a resonant return. Apophis will have a close Earth-encounter in 2029 with potential very close subsequent Earth-encounters (or even an impact) in 2036 or later, depending on whether it passes through one of several so-called gravitational keyholes during its 2029-encounter. Several pre-2029-deflection scenarios to prevent Apophis from doing this have been investigated so far. Because the keyholes are less than 1 km in size, a pre-2029 kinetic impact is clearly the best option because it requires only a small change in Apophis' orbit to nudge it out of a keyhole. A single solar sail Kinetic Energy Impactor (KEI) spacecraft that impacts Apophis from a retrograde trajectory with a very high relative velocity (75-80 km/s) during one of its perihelion passages at about 0.75 AU would be a feasible option to do this. The spacecraft consists of a 160 m x 160 m, 168 kg solar sail assembly and a 150 kg impactor. Although conventional spacecraft can also achieve the required minimum deflection of 1 km for this approx. 320 m-sized object from a prograde trajectory, our solar sail KEI concept also allows the deflection of larger objects. In this paper, we also show that, even after Apophis has flown through one of the gravitational keyholes in 2029, solar sail Kinetic Energy Impactor (KEI) spacecraft are still a feasible option to prevent Apophis from impacting the Earth, but many KEIs would be required for consecutive impacts to increase the total Earth-miss distance to a safe value. In this paper, we elaborate potential pre- and post-2029 KEI impact scenarios for a launch in 2020, and investigate tradeoffs between different mission parameters.
KW  - Solar Sail
KW  - Asteroid Deflection
KW  - Planetary Protection
KW  - Trajectory Optimization
Y1  - 2006
U6  - http://dx.doi.org/10.2514/6.2006-6178
N1  - AIAA/AAS Astrodynamics Specialist Conference and Exhibit, 21 August 2006 - 24 August 2006, Keystone, Colorado(USA).
SP  - 1
EP  - 20
ER  - 
TY  - CHAP
A1  - Huth, Thomas
A1  - Elsen, Olaf
A1  - Hartwig, Christoph
A1  - Esch, Thomas
T1  - Innovative modular valve trains for 2015 - logistic benefits by EMVT
T2  - IFAC Proceedings Volumes, Volume 39, Issue 3
N2  - In this paper the way to a 5-day-car with respect to a modular valve train systems for spark ignited combustion engines is shown. The necessary product diversity is shift from mechanical or physical components to software components. Therefore, significant improvements of logistic indicators are expected and shown. The working principle of a camless cylinder head with respect to an electromagnetical valve train (EMVT) is explained and it is demonstrated that shifting physical diversity to software is feasible. The future design of combustion engine systems including customisation can be supported by a set of assistance tools which is shown exemplary.
Y1  - 2006
U6  - http://dx.doi.org/10.3182/20060517-3-FR-2903.00172
N1  - Part of special issue "12th IFAC Symposium on Information Control Problems in Manufacturing"
SP  - 315
EP  - 320
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Ohndorf, A.
T1  - 1st ACT Global Trajectory Optimisation Competition : Results found at DLR
JF  - Acta Astronautica. 61 (2007), H. 9
Y1  - 2007
SN  - 0094-5765
N1  - Global Trajectory Optimization ;  Results of the First Competition Organised by the Advanced Concept Team (ACT) of the European Space Agency (ESA)
SP  - 742
EP  - 752
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - McDonald, Malcolm
A1  - McInnes, Colin R.
A1  - Mengali, Giovanni
T1  - Impact of Optical Degradation on Solar Sail Mission Performance
JF  - Journal of Spacecraft and Rockets. 44 (2007), H. 4
Y1  - 2007
SN  - 0022-4650
N1  - 2. ISSN: 1533-6794
SP  - 740
EP  - 749
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Wi, Bong
T1  - Solar Sail Kinetic Energy Impactor Trajectory Optimization for an Asteroid-Deflection Mission
JF  - Journal of Spacecraft and Rockets. 44 (2007), H. 4
Y1  - 2007
SN  - 0022-4650
N1  - 2. ISSN: 1533-6794
SP  - 755
EP  - 764
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Mengali, Giovanni
A1  - Quarta, Alessandro A.
A1  - Circi, Christian
T1  - Refined Solar Sail Force Model with Mission Application / Giovanni Mengali ; Alessandro A. Quarta , Christian Circi ;  Bernd Dachwald
JF  - Journal of Guidance, Control, and Dynamics. 30 (2007), H. 2
Y1  - 2007
SN  - 0162-3192
N1  - 2. ISBN: 0731-5090
SP  - 512
EP  - 520
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - MacDonald, Malcolm
A1  - McInnes, Colin R.
T1  - Heliocentric Solar Sail Orbit Transfers with Locally Optimal Control Laws / Malcolm Macdonald ; Colin McInnes ; Bernd Dachwald
JF  - Journal of Spacecraft and Rockets. 44 (2007), H. 1
Y1  - 2007
SN  - 0022-4650
SP  - 273
EP  - 276
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Carnelli, I.
A1  - Vasile, M.
T1  - Optimizing low-thrust gravity assist interplanetary trajectories using evolutionary neurocontrollers / I. Carnelli ; B. Dachwald ; M. Vasile
JF  - IEEE Congress on Evolutionary Computation, 2007 : CEC 2007 ; 25 - 28 September 2007, Singapore
Y1  - 2007
SN  - 978-1-424-41339-3
N1  - ISBN 10: 1-424-41339-7 ; IEEE Congress on Evolutionary Computation <2007, Singapore> ; 	Institute of Electrical and Electronics Engineers ; Nebent: CEC 2007 ; Parallel als Online-Ausg. erschienen
SP  - 965
EP  - 972
PB  - IEEE Service Center
CY  - Piscataway, NJ
ER  - 
TY  - JOUR
A1  - Ley, Wilfried
A1  - Plescher, Engelbert
A1  - Scholz, Artur
A1  - Piepenbrock, Johannes
T1  - COMPASS-1 picosatellite project / Ley, Wilfried ; Plescher, Engelbert ; Scholz, Artur ; Piepenbrock, Johannes
JF  - Small satellites for earth observation : digest of the 6th International symposium of the International Academy of Astronautics, Berlin, April 23 - 26, 2007 / ed. by Rainer Sandau; Hans-Peter Röser; Arnoldo Valenzuela
Y1  - 2007
SN  - 9783896855718
N1  - Symposium on Small Satellites for Earth Observation ; (6, 2007, Berlin)
SP  - 147
EP  - 150
PB  - Wissenschaft und Technik Verl.
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Wittmann, Klaus
A1  - Bibring, J.-P.
A1  - Rosenbauer, H.
A1  - Boehnhardt, H.
T1  - The Rosetta Lander (“Philae”) Investigations  / Bibring, J.-P. ; Rosenbauer, H. ; Boehnhardt, H. ;  [...] Wittmann, K.
JF  - Space Science Reviews. 128 (2007), H. 1-4
Y1  - 2007
SN  - 0038-6308
SP  - 205
EP  - 220
ER  - 
TY  - JOUR
A1  - Overduin, James
A1  - Blome, Hans-Joachim
A1  - Hoell, Josef
T1  - Wolfgang Priester: from the big bounce to the Lambda-dominated universe
JF  - Naturwissenschaften
Y1  - 2007
SN  - 0028-1042
VL  - 94
IS  - 6
SP  - 417
EP  - 429
ER  - 
TY  - JOUR
A1  - Funke, Harald
A1  - Robinson, A. E.
T1  - Development of a new test rig for a micro scale hydrogen combustion chamber
JF  - Proceedings of the 2nd European Conference for Aero-Space Sciences : July 1 - 6, 2007, Brussels, Belgium
Y1  - 2007
N1  - European Conference for Aerospace Sciences <2, 2007, Brüssel> ; EUCASS <2, 2007, Brüssel> ; Paper No. 22
SP  - 1
EP  - 8
PB  - -
ER  - 
TY  - JOUR
A1  - Bécret, P.
A1  - Grossen, J.
A1  - Trilla, J.
A1  - Robinson, A.
A1  - Bosschaerts, W.
A1  - Funke, Harald
A1  - Hendrick, P.
T1  - Testing and numerical study of a 10 kW hydrogen micro combustor
JF  - International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications <7, 2007, Freiburg, Breisgau>  ; PowerMEMS ; 7
Y1  - 2007
SP  - 367
EP  - 370
ER  - 
TY  - JOUR
A1  - Robinson, A. E.
A1  - Rönna, Uwe
A1  - Funke, Harald
T1  - Testing of a 10 kW diffusive micro-mix combustor for hydrogen-fuelled micro-scale gas turbines
JF  - International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications <7, 2007, Freiburg, Breisgau>  ; PowerMEMS ; 7
Y1  - 2007
SP  - 225
EP  - 228
ER  - 
TY  - JOUR
A1  - McArdell, Brian W.
A1  - Bartelt, Perry
A1  - Kowalski, Julia
T1  - Field observations of basal forces and fluid pore pressure in a debris flow
JF  - Geophysical Research Letters (GRL)
N2  - Using results from an 8 m2 instrumented force plate we describe field measurements of normal and shear stresses, and fluid pore pressure for a debris flow. The flow depth increased from 0.1 to 1 m within the first 12 s of flow front arrival, remained relatively constant until 100 s, and then gradually decreased to 0.5 m by 600 s. Normal and shear stresses and pore fluid pressure varied in-phase with the flow depth. Calculated bulk densities are ρb = 2000–2250 kg m−3 for the bulk flow and ρf = 1600–1750 kg m−3 for the fluid phase. The ratio of effective normal stress to shear stress yields a Coulomb basal friction angle of ϕ = 26° at the flow front. We did not find a strong correlation between the degree of agitation in the flow, estimated using the signal from a geophone on the force plate, and an assumed dynamic pore fluid pressure. Our data support the idea that excess pore-fluid pressures are long lived in debris flows and therefore contribute to their unusual mobility.
KW  - debris flow
Y1  - 2007
SN  - 0094-8276
VL  - 34
IS  - 7
ER  - 
TY  - CHAP
A1  - Kowalski, Julia
A1  - Bartelt, Perry
A1  - McElwaine, J.
T1  - Two-phase debris flow modeling
T2  - Geophysical Research Abstracts
Y1  - 2007
N1  - A-08119
ER  - 
TY  - CHAP
A1  - Reimer, Lars
A1  - Braun, Carsten
A1  - Chen, B.-H.
A1  - Ballmann, Josef
T1  - Computational aeroelastic analysis and design of the HIRENASD wind tunnel wing model and tests
T2  - Proceedings / IFASD 2007, CEAS/AIAA/KTH International Forum on Aeroelasticity and Structural Dynamics : June 18 - 21, 2007, Stockholm, Sweden
Y1  - 2007
PB  - KTH
CY  - Stockholm
ER  - 
TY  - CHAP
A1  - Wellmer, Georg
A1  - Chen, B.-H.
A1  - Braun, Carsten
A1  - Ballmann, Josef
T1  - Numerical prediction of aeroelastic effects on twin-sting-rig mounted models for rear fuselage and empennage flow investigation in transonic windtunnel
T2  - Proceedings / IFASD 2007, CEAS/AIAA/KTH International Forum on Aeroelasticity and Structural Dynamics, June 18 - 21, 2007, Stockholm, Sweden
Y1  - 2007
PB  - KTH
CY  - Stockholm
ER  - 
TY  - CHAP
A1  - Reimer, Lars
A1  - Braun, Carsten
A1  - Ballmann, Josef
T1  - Computational study of the aeroelastic equilibrium configuration of a swept wind tunnel wing model in subsonic flow
T2  - High performance computing in science and engineering '06. Transactions of the High Performance Computing Center Stuttgart (HLRS) 2006 /  Wolfgang E. Nagel ... Eds.
N2  - In the Collaborative Research Center SFB 401 at RWTH Aachen University, the numerical aeroelastic method SOFIA for direct numerical aeroelastic simulation is being progressively developed. Numerical results obtained by applying SOFIA were compared with measured data of static and dynamic aeroelastic wind tunnel tests for an elastic swept wing in subsonic flow.
Y1  - 2007
SN  - 978-3-540-36165-7
SP  - 421
EP  - 434
PB  - Springer
CY  - Berlin [u.a.]
ER  - 
TY  - CHAP
A1  - Dachwald, Bernd
T1  - Low-Thrust Mission Analysis and Global Trajectory Optimization Using Evolutionary Neurocontrol: New Results
T2  - European Workshop on Space Mission Analysis ESA/ESOC, Darmstadt, Germany 10 { 12 Dec 2007
N2  - Interplanetary trajectories for low-thrust spacecraft are often characterized by multiple revolutions around the sun. Unfortunately, the convergence of traditional trajectory optimizers that are based on numerical optimal control methods depends strongly on an adequate initial guess for the control function (if a direct method is used) or for the starting values of the adjoint vector (if an indirect method is used). Especially when many revolutions around the sun are re-
quired, trajectory optimization becomes a very difficult and time-consuming task that involves a lot of experience and expert knowledge in astrodynamics and optimal control theory, because an adequate initial guess is extremely hard to find. Evolutionary neurocontrol (ENC) was proposed as a smart method for low-thrust trajectory optimization that fuses artificial neural networks and evolutionary algorithms to so-called evolutionary neurocontrollers (ENCs) [1]. Inspired by natural archetypes, ENC attacks the trajectoryoptimization problem from the perspective of artificial intelligence and machine learning, a perspective that is quite different from that of optimal control theory. Within the context of ENC, a trajectory is regarded as the result of a spacecraft steering strategy that maps permanently the actual spacecraft state and the actual target state onto the actual spacecraft control vector. This way, the problem of searching the optimal spacecraft trajectory is equivalent to the problem of searching (or "learning") the optimal spacecraft steering strategy. An artificial neural network is used to implement such a spacecraft steering strategy. It can be regarded as a parameterized function (the network function) that is defined by the internal network parameters. Therefore, each distinct set of network parameters defines a different network function and thus a different steering strategy. The problem of searching the optimal steering strategy is now equivalent to the problem of searching the optimal set of network parameters. Evolutionary algorithms that work on a population of (artificial) chromosomes are used to find the optimal network parameters, because the parameters can be easily mapped onto a chromosome. The trajectory optimization problem is solved when the optimal chromosome is found. A comparison of solar sail trajectories that have been published by others [2, 3, 4, 5] with ENC-trajectories has shown that ENCs can be successfully applied for near-globally optimal spacecraft control [1, 6] and that they are able to find trajectories that are closer to the (unknown) global optimum, because they explore the trajectory search space more exhaustively than a human expert can do. The obtained trajectories are fairly accurate with respect to the terminal constraint. If a more accurate trajectory is required, the ENC-solution can be used as an initial guess for a local trajectory optimization method. Using ENC, low-thrust trajectories can be optimized without an initial guess and without expert attendance.
Here, new results for nuclear electric spacecraft and for solar sail spacecraft are presented and it will be shown that ENCs find very good trajectories even for very difficult problems. Trajectory optimization results are presented for 1. NASA's Solar Polar Imager Mission, a mission to attain a highly inclined close solar orbit with a solar sail [7] 2. a mission to de ect asteroid Apophis with a solar sail from a retrograde orbit with a very-high velocity impact [8, 9] 3. JPL's \2nd Global Trajectory Optimization Competition", a grand tour to visit four asteroids from different classes with a NEP spacecraft
Y1  - 2007
ER  - 
TY  - CHAP
A1  - Dachwald, Bernd
A1  - Seboldt, Wolfgang
A1  - Loeb, Horst W.
A1  - Schartner, Karl-Heinz
T1  - A comparison of SEP and NEP for a main belt asteroid sample return mission
T2  - 7th International Symposium on Launcher Technologies, Barcelona, Spain, 02-05 April 2007
N2  - Innovative interplanetary deep space missions, like a main belt asteroid sample
return mission, require ever larger velocity increments (∆V s) and thus ever
more demanding propulsion capabilities. Providing much larger exhaust velocities than chemical high-thrust systems, electric low-thrust space-propulsion
systems can significantly enhance or even enable such high-energy missions. In
1995, a European-Russian Joint Study Group (JSG) presented a study report
on “Advanced Interplanetary Missions Using Nuclear-Electric Propulsion”
(NEP). One of the investigated reference missions was a sample return (SR)
from the main belt asteroid (19) Fortuna. The envisaged nuclear power plant,
Topaz-25, however, could not be realized and also the worldwide developments
in space reactor hardware stalled. In this paper, we investigate, whether such
a mission is also feasible using a solar electric propulsion (SEP) system and
compare our SEP results to corresponding NEP results.
Y1  - 2007
SP  - 1
EP  - 10
ER  - 
TY  - CHAP
A1  - Dachwald, Bernd
A1  - Kahle, Ralph
A1  - Wie, Bong
T1  - Head-on impact deflection of NEAs: a case study for 99942 Apophis
T2  - Planetary Defense Conference 2007
N2  - Near-Earth asteroid (NEA) 99942 Apophis provides a typical example for the evolution of asteroid orbits that lead to Earth-impacts after a close Earth-encounter that results in a resonant return. Apophis will have a close Earth-encounter in 2029 with potential very close subsequent Earth-encounters (or even an impact) in 2036 or later, depending on whether it passes through one of several less than 1 km-sized gravitational keyholes during its 2029-encounter. A pre-2029 kinetic impact is a very favorable option to nudge the asteroid out of a keyhole. The highest impact velocity and thus deflection can be achieved from a trajectory that is retrograde to Apophis orbit. With a chemical or electric propulsion system, however, many gravity assists and thus a long time is required to achieve this. We show in this paper that the solar sail might be the better propulsion system for such a mission: a solar sail Kinetic Energy Impactor (KEI) spacecraft could impact Apophis from a retrograde trajectory with a very high relative velocity (75-80 km/s) during one of its perihelion passages. The spacecraft consists of a 160 m × 160 m, 168 kg solar sail assembly and a 150 kg impactor. Although conventional spacecraft can also achieve the required minimum deflection of 1 km for this approx. 320 m-sized object from a prograde trajectory, our solar sail KEI concept also allows the deflection of larger objects. For a launch in 2020, we also show that, even after Apophis has flown through one of the gravitational keyholes in 2029, the solar sail KEI concept is still feasible to prevent Apophis from impacting the Earth, but many KEIs would be required for consecutive impacts to increase the total Earth-miss distance to a safe value
Y1  - 2007
N1  - Planetary Defense Conference 2007, Wahington D.C., USA, 05-08 March 2007
SP  - 1
EP  - 12
ER  - 
TY  - CHAP
A1  - Loeb, Horst Wolfgang
A1  - Schartner, Karl-Heinz
A1  - Dachwald, Bernd
A1  - Seboldt, Wolfgang
T1  - SEP-Sample return from a main belt asteroid
T2  - 30th International Electric Propulsion Conference
N2  - By DLR-contact, sample return missions to the large main-belt asteroid “19, Fortuna” have been studied. The mission scenario has been based on three ion thrusters of the RIT-22 model, which is presently under space qualification, and on solar arrays equipped with triple-junction GaAs solar cells. After having designed the spacecraft, the orbit-to-orbit trajectories for both, a one-way SEP mission with a chemical sample return and an all-SEP return mission, have been optimized using a combination of artificial neural networks with evolutionary algorithms. Additionally, body-to-body trajectories have been
investigated within a launch period between 2012 and 2015. For orbit-to-orbit calculation, the launch masses of the hybrid mission and of the all-SEP mission resulted in 2.05 tons and 1.56 tons, respectively, including a scientific payload of 246 kg. For the related transfer
durations 4.14 yrs and 4.62 yrs were obtained. Finally, a comparison between the mission scenarios based on SEP and on NEP have been carried out favouring clearly SEP.
Y1  - 2007
SP  - 1
EP  - 11
ER  - 
TY  - CHAP
A1  - Dachwald, Bernd
A1  - Mengali, Giovanni
A1  - Quarta, Alessandro A
A1  - Macdonald, Malcolm
A1  - McInnes, Colin R
T1  - Optical solar sail degradation modelling
T2  - 1st International Symposium on Solar Sailing
N2  - We propose a simple parametric OSSD model that describes the variation of the sail film's optical coefficients with time, depending on the sail film's environmental history, i.e., the radiation dose. The primary intention of our model is not to describe the exact behavior of specific film-coating combinations in the real space environment, but to provide a more general parametric framework for describing the general optical degradation behavior of solar sails.
Y1  - 2007
N1  - 1st International Symposium on Solar Sailing 27–29 June 2007, Herrsching, Germany
SP  - 1
EP  - 27
ER  - 
TY  - CHAP
A1  - Weiss, Alexander
A1  - Abanteriba, Sylvester
A1  - Esch, Thomas
T1  - Investigation of Flow Separation Inside a Conical Rocket Nozzle With the Aid of an Annular Cross Flow
T2  - Proceedings of the ASME/JSME 2007 5th Joint Fluids Engineering Conference. Volume 1: Symposia, Parts A and B
N2  - Flow separation is a phenomenon that occurs in all kinds of supersonic nozzles sometimes during run-up and shut-down operations. Especially in expansion nozzles of rocket engines with large area ratio, flow separation can trigger strong side loads that can damage the structure of the nozzle. The investigation presented in this paper seeks to establish measures that may be applied to alter the point of flow separation. In order to achieve this, a supersonic nozzle was placed at the exit plane of the conical nozzle. This resulted in the generation of cross flow surrounding the core jet flow from the conical nozzle. Due to the entrainment of the gas stream from the conical nozzle the pressure in its exit plane was found to be lower than that of the ambient. A Cold gas instead of hot combustion gases was used as the working fluid. A mathematical simulation of the concept was validated by experiment. Measurements confirmed the simulation results that due to the introduction of a second nozzle the pressure in the separated region of the conical nozzle was significantly reduced. It was also established that the boundary layer separation inside the conical nozzle was delayed thus allowing an increased degree of overexpansion. The condition established by the pressure measurements was also demonstrated qualitatively using transparent nozzle configurations.
Y1  - 2007
SN  - 0-7918-4288-6
U6  - http://dx.doi.org/10.1115/FEDSM2007-37387
N1  - Proceedings of the ASME/JSME 2007 5th Joint Fluids Engineering Conference. Volume 1: Symposia, Parts A and B. San Diego, California, USA. July 30–August 2, 2007
SP  - 1861
EP  - 1871
PB  - American Society of Mechanical Engineers (ASME)
CY  - New York
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Seboldt, W.
A1  - Loeb, H. W
A1  - Schartner, K.-H.
T1  - Main Belt Asteroid Sample Return Mission Using Solar Electric Propulsion
JF  - Acta Astronautica. 63 (2008), H. 1-4
Y1  - 2008
SN  - 0094-5765
N1  - International Astronautical Federation Congress <58, 2007, Hyderabad> ; International Astronautical Congress <58, 2007, Hyderabad> ; IAC-07-A3.5.07
SP  - 91
EP  - 101
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Seboldt, W.
T1  - Solar Sails — Propellantless Propulsion for Near- and Medium-Term Deep-Space Missions  / W. Seboldt ; B. Dachwald
JF  - Advanced Propulsion Systems and Technologies, Today to 2020 / Claudio Bruno (ed.) ... - (Progress in Astronautics and Aeronautics Series ; 223)
Y1  - 2008
SN  - 978-1-56347-929-8
N1  - ISBN 10: 1-56347-929-X  ; American Institute of Aeronautics and Astronautics <New York, NY>
PB  - AIAA
CY  - Reston, Va.
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Seboldt, W.
A1  - Lämmerzahl, W.
T1  - Solar Sail Propulsion: An Enabling Technology for Fundamental Physics Missions
JF  - Lasers, Clocks and Drag Free Control : Exploration of Relativistic Gravity in Space / by Hansjörg Dittus ..., eds. - ( Astrophysics and Space Science Library ; 349)
Y1  - 2008
SN  - 978-3-540-34376-9
SP  - 379
EP  - 398
PB  - Springer
CY  - Berlin [u.a.]
ER  - 
TY  - JOUR
A1  - Trilla, Joan
A1  - Grossen, Jürgen
A1  - Robinson, Alexander
A1  - Funke, Harald
A1  - Bosschaerts, Walter
A1  - Hendrick, Patrick
T1  - Development of a hydrogen combustion chamber for an ultra micro gas turbine
JF  - PowerMEMS 2008, 8th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications, microEMS 2008, 2nd Symposium on Micro Environmental Machine Systems, Sendai, JP, Nov 9-12, 2008
Y1  - 2008
SP  - 101
EP  - 104
ER  - 
TY  - JOUR
A1  - Robinson, A. E.
A1  - Funke, Harald
A1  - Hendrick, P.
A1  - Recker, E.
A1  - Peirs, J.
T1  - Development of a hydrogen fuelled 1 kW ultra micro gas turbine with special respect to designing, testing and mapping of the µ-scale combustor
JF  - IEEE International Conference on Sustainable Energy Technologies, 2008 : ICSET 2008 ; Singapore, 24 - 27 Nov. 2008.
Y1  - 2008
SN  - 978-1-4244-1887-9
SP  - 656
EP  - 660
PB  - IEEE
CY  - Piscataway, NJ
ER  - 
TY  - JOUR
A1  - Havermann, Marc
A1  - Haertig, J.
A1  - Rey, C.
A1  - George, A.
T1  - PIV Measurements in Shock Tunnels and Shock Tubes / Havermann, M. ; Haertig, J. ; Rey, C. ; George, A.
JF  - Particle Image Velocimetry : New Developments and Recent Applications
Y1  - 2008
SN  - 978-3-540-73528-1
N1  - Topics in applied physics. Vol 112.
SP  - 429
EP  - 442
PB  - Springer
CY  - Berlin
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  - Funke, Harald
A1  - Rönna, Uwe
A1  - Robinson, A. E.
T1  - Development and testing of a 10 kW diffusive micromix combustor for hydrogen-fuelled μ-scale gas turbines
JF  - Proceedings of ASME Turbo Expo 2008: Power for Land, Sea and Air ; GT2008 ; June 9-13, 2008, Berlin, Germany
Y1  - 2008
N1  - GT2008-50418
SP  - 1
EP  - 8
PB  - ASME
CY  - New York, NY
ER  - 
TY  - CHAP
A1  - Christen, Marc
A1  - Bartelt, Perry
A1  - Kowalski, Julia
A1  - Stoffel, Lukus
T1  - Calculation of dense snow avalanches in three-dimensional terrain with the numerical simulation programm RAMMS
T2  - Proceedings ISSW 2008 ; International Snow Science Workshop. Whistler 2008
N2  - Numerical models have become an essential part of snow avalanche engineering. Recent
advances in understanding the rheology of flowing snow and the mechanics of entrainment and
deposition have made numerical models more reliable. Coupled with field observations and historical
records, they are especially helpful in understanding avalanche flow in complex terrain. However, the
application of numerical models poses several new challenges to avalanche engineers. A detailed
understanding of the avalanche phenomena is required to specify initial conditions (release zone
dimensions and snowcover entrainment rates) as well as the friction parameters, which are no longer
based on empirical back-calculations, rather terrain roughness, vegetation and snow properties. In this
paper we discuss these problems by presenting the computer model RAMMS, which was specially
designed by the SLF as a practical tool for avalanche engineers. RAMMS solves the depth-averaged
equations governing avalanche flow with first and second-order numerical solution schemes. A
tremendous effort has been invested in the implementation of advanced input and output features.
Simulation results are therefore clearly and easily visualized to simplify their interpretation. More
importantly, RAMMS has been applied to a series of well-documented avalanches to gauge model
performance. In this paper we present the governing differential equations, highlight some of the input
and output features of RAMMS and then discuss the simulation of the Gatschiefer avalanche that
occurred in April 2008, near Klosters/Monbiel, Switzerland.
KW  - snow
KW  - avalanche
Y1  - 2008
SP  - 709
EP  - 716
ER  - 
TY  - THES
A1  - Kowalski, Julia
T1  - Two-phase Modeling of Debris Flows
Y1  - 2008
SN  - 978-3-86664-524-0
N1  - Diss., Eidgenössische Technische Hochschule ETH Zürich, Nr. 17827, 2008
PB  - Mensch und Buch
CY  - Berlin
ER  - 
TY  - CHAP
A1  - Kowalski, Julia
A1  - McElwaine, J.
T1  - Two-phase debris flow modeling
T2  - Geophysical Research Abstracts
Y1  - 2008
N1  - A-01048
ER  - 
TY  - CHAP
A1  - Nowack, N.
A1  - Röth, Thilo
A1  - Bührig-Polaczek, A.
A1  - Klaus, G.
ED  - Hirsch, Jürgen
T1  - Advanced Sheet Metal Components Reinforced by Light Metal Cast Structures
T2  - Aluminium alloys : their physical and mechanical properties ; [proceedings of the 11th International Conference on Aluminium Alloys, 22 - 26 Sept. 2008, Aachen, Germany ; ICAA 11]
Y1  - 2008
SN  - 978-3-527-32367-8
IS  - 2
SP  - 2374
EP  - 2381
ER  - 
TY  - CHAP
A1  - Digel, Ilya
A1  - Dachwald, Bernd
A1  - Artmann, Gerhard
A1  - Linder, Peter
A1  - Funke, O.
T1  - A concept of a probe for particle analysis and life detection in icy environments
N2  - A melting probe equipped with autofluorescence-based detection system combined with a light scattering unit, and, optionally, with a microarray chip would be ideally suited to probe icy environments like Europa’s ice layer as well as the polar ice layers of Earth and Mars for recent and extinct live.
KW  - Sonde
KW  - Eisschicht
KW  - Autofluoreszenzverfahren
KW  - Lichtstreuungsbasierte Instrumente
KW  - autofluorescence-based detection system
KW  - light scattering analysis
Y1  - 2009
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Ohndorf, A.
A1  - Gill, E.
T1  - Optimization of low-thrust Earth-Moon transfers using evolutionary neurocontrol  / Ohndorf, A. ; Dachwald, B. ; Gill, E.
JF  - IEEE Congress on Evolutionary Computation, 2009. CEC '09.
Y1  - 2009
SN  - 978-1-4244-2958-5
SP  - 358
EP  - 364
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Carnelli, Ian
A1  - Vasile, Massimiliano
T1  - Evolutionary Neurocontrol: A Novel Method for Low-Thrust Gravity-Assist Trajectory Optimization / Carnelli, Ian ; Dachwald, Bernd ; Vasile, Massimiliano
JF  - Journal of guidance control and dynamics. 32 (2009), H. 2
Y1  - 2009
SN  - 0731-5090
SP  - 616
EP  - 625
PB  - AIAA
CY  - Reston, Va.
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Ball, Andrew J.
A1  - Ulamec, Stephan
A1  - Price, Michael E.
T1  - A small mission for in situ exploration of a primitive binary near-Earth asteroid  / Ball, Andrew J. ; Ulamec, Stephan ; Dachwald, Bernd ; Price, Michael E. ; [u.a.]
JF  - Advances in Space Research. 43 (2009), H. 2
Y1  - 2009
SN  - 0273-1177
SP  - 317
EP  - 324
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - BOOK
A1  - Ley, Wilfried
A1  - Wittmann, Klaus
A1  - Hallmann, Willi
T1  - Handbook of space technology
Y1  - 2009
SN  - 978-0-470-69739-9
PB  - Wiley
CY  - Chichester
ER  - 
TY  - JOUR
A1  - Wilson, T. L.
A1  - Blome, Hans-Joachim
T1  - The Pioneer anomaly and a rotating Gödel universe
JF  - Advances in Space Research
Y1  - 2009
SN  - 0273-1177
VL  - 44
IS  - 11
SP  - 1345
EP  - 1353
ER  - 
TY  - JOUR
A1  - Robinson, A. E.
A1  - Funke, Harald
A1  - Wagemakers, R.
A1  - Grossen, J.
A1  - Bosschaerts, W.
A1  - Hendrick, P.
T1  - Numerical and Experimental Investigation of a Micromix Combustor for a Hydrogen Fuelled μ-Scale Gas Turbine
JF  - Proceedings of the ASME Turbo Expo 2009 : : presented at the 2009 ASME Turbo Expo, June 8 - 12, 2009, Orlando, Florida, USA / sponsored by the International Gas Turbine Institute
Y1  - 2009
SN  - 9780791848869
N1  - GT2009-60061
SP  - 253
EP  - 262
PB  - ASME
CY  - New York, NY
ER  - 
TY  - JOUR
A1  - Pichler, A.
A1  - George, A.
A1  - Seiler, F.
A1  - Srulijes, J.
A1  - Havermann, Marc
T1  - Doppler Picture Velocimetry (DPV) applied to hypersonics
JF  - Shock Waves [Elektronische Ressource] : 26th International Symposium on Shock Waves, Volume 1 / edited by Klaus Hannemann, Friedrich Seiler
Y1  - 2009
SN  - 978-3-540-85168-4
N1  - International Symposium on Shock Waves ; (26 ; 2007.07.15-20 ; Göttingen) ; ISSW ; (26 ; 2007.07.15-20 ; Göttingen)
SP  - 503
EP  - 508
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Fischer, Jan-Thomas
A1  - Kowalski, Julia
A1  - Pudasaini, Shiva P.
A1  - Miller, S. A.
T1  - Dynamic Avalanche Modeling in Natural Terrain
JF  - International Snow Science Workshop, Davos 2009, Proceedings ; Proc. ISSW 2009
N2  - The powerful avalanche simulation toolbox RAMMS (Rapid Mass Movements) is based on a depth-averaged
hydrodynamic system of equations with a Voellmy-Salm friction relation. The two empirical friction parameters
μ and �  correspond to a dry Coulomb friction and a viscous resistance, respectively. Although μ and � lack a
proper physical explanation, 60 years of acquired avalanche data in the Swiss Alps made a systematic calibration
possible. RAMMS can therefore successfully model avalanche flow depth, velocities, impact pressure and run
out distances. Pudasaini and Hutter (2003) have proposed extended, rigorously derived model equations that
account for local curvature and twist. A coordinate transformation into a reference system, applied to the actual
mountain topography of the natural avalanche path, is performed. The local curvature and the twist of the
avalanche path induce an additional term in the overburden pressure. This leads to a modification of the Coulomb
friction, the free-surface pressure gradient, the pressure induced by the channel, and the gravity components
along and normal to the curved and twisted reference surface. This eventually guides the flow dynamics and
deposits of avalanches. In the present study, we investigate the influence of curvature on avalanche flow in
real mountain terrain. Simulations of real avalanche paths are performed and compared for the different models
approaches. An algorithm to calculate curvature in real terrain is introduced in RAMMS. This leads to a curvature
dependent friction relation in an extended version of the Voellmy-Salm model equations. Our analysis provides
yet another step in interpreting the physical meaning and significance of the friction parameters used in the
RAMMS computational environment.
KW  - snow
KW  - avalanche
Y1  - 2009
SP  - 448
EP  - 452
ER  - 
TY  - CHAP
A1  - Börner, Sebastian
A1  - Funke, Harald
A1  - Hendrick, P.
A1  - Recker, E.
T1  - LES of Jets In Cross-Flow and Application to the “Micromix” Hydrogen Combustion
T2  - XIX International Symposium on Air Breathing Engines 2009 (ISABE 2009) : Proceedings of a meeting held 7-11 September 2009, Montreal, Canada
Y1  - 2009
SN  - 9781615676064
SP  - 1555
EP  - 1561
ER  -