@article{DachwaldMacDonaldMcInnes2007,
  author    = {Dachwald, Bernd and MacDonald, Malcolm and McInnes, Colin R.},
  title     = {Heliocentric Solar Sail Orbit Transfers with Locally Optimal Control Laws / Malcolm Macdonald ; Colin McInnes ; Bernd Dachwald},
  series = {Journal of Spacecraft and Rockets. 44 (2007), H. 1},
  journal   = {Journal of Spacecraft and Rockets. 44 (2007), H. 1},
  isbn      = {0022-4650},
  pages     = {273 -- 276},
  year      = {2007},
  language  = {en}
}
@incollection{ReimerBraunBallmann2007,
  author    = {Reimer, Lars and Braun, Carsten and Ballmann, Josef},
  title     = {Computational study of the aeroelastic equilibrium configuration of a swept wind tunnel wing model in subsonic flow},
  series = {High performance computing in science and engineering '06. Transactions of the High Performance Computing Center Stuttgart (HLRS) 2006 / Wolfgang E. Nagel ... Eds.},
  booktitle = {High performance computing in science and engineering '06. Transactions of the High Performance Computing Center Stuttgart (HLRS) 2006 / Wolfgang E. Nagel ... Eds.},
  publisher = {Springer},
  address   = {Berlin [u.a.]},
  isbn      = {978-3-540-36165-7},
  pages     = {421 -- 434},
  year      = {2007},
  abstract  = {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.},
  language  = {en}
}
@article{DachwaldOhndorf2007,
  author    = {Dachwald, Bernd and Ohndorf, A.},
  title     = {1st ACT Global Trajectory Optimisation Competition : Results found at DLR},
  series = {Acta Astronautica. 61 (2007), H. 9},
  journal   = {Acta Astronautica. 61 (2007), H. 9},
  isbn      = {0094-5765},
  pages     = {742 -- 752},
  year      = {2007},
  language  = {en}
}
@inproceedings{DachwaldSeboldtLoebetal.2007,
  author    = {Dachwald, Bernd and Seboldt, Wolfgang and Loeb, Horst W. and Schartner, Karl-Heinz},
  title     = {A comparison of SEP and NEP for a main belt asteroid sample return mission},
  series = {7th International Symposium on Launcher Technologies, Barcelona, Spain, 02-05 April 2007},
  booktitle = {7th International Symposium on Launcher Technologies, Barcelona, Spain, 02-05 April 2007},
  pages     = {1 -- 10},
  year      = {2007},
  abstract  = {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.},
  language  = {en}
}
@inproceedings{DachwaldKahleWie2007,
  author    = {Dachwald, Bernd and Kahle, Ralph and Wie, Bong},
  title     = {Head-on impact deflection of NEAs: a case study for 99942 Apophis},
  series = {Planetary Defense Conference 2007},
  booktitle = {Planetary Defense Conference 2007},
  pages     = {1 -- 12},
  year      = {2007},
  abstract  = {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},
  language  = {en}
}
@inproceedings{Dachwald2007,
  author    = {Dachwald, Bernd},
  title     = {Low-Thrust Mission Analysis and Global Trajectory Optimization Using Evolutionary Neurocontrol: New Results},
  series = {European Workshop on Space Mission Analysis ESA/ESOC, Darmstadt, Germany 10 { 12 Dec 2007},
  booktitle = {European Workshop on Space Mission Analysis ESA/ESOC, Darmstadt, Germany 10 { 12 Dec 2007},
  year      = {2007},
  abstract  = {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},
  language  = {en}
}
@inproceedings{WeissAbanteribaEsch2007,
  author    = {Weiss, Alexander and Abanteriba, Sylvester and Esch, Thomas},
  title     = {Investigation of Flow Separation Inside a Conical Rocket Nozzle With the Aid of an Annular Cross Flow},
  series = {Proceedings of the ASME/JSME 2007 5th Joint Fluids Engineering Conference. Volume 1: Symposia, Parts A and B},
  booktitle = {Proceedings of the ASME/JSME 2007 5th Joint Fluids Engineering Conference. Volume 1: Symposia, Parts A and B},
  publisher = {American Society of Mechanical Engineers (ASME)},
  address   = {New York},
  isbn      = {0-7918-4288-6},
  doi       = {10.1115/FEDSM2007-37387},
  pages     = {1861 -- 1871},
  year      = {2007},
  abstract  = {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.},
  language  = {en}
}
@article{HennPolaczek2007,
  author    = {Henn, Gudrun and Polaczek, Christa},
  title     = {Studienerfolg in den Ingenieurwissenschaften},
  series = {Das Hochschulwesen : HSW ; Forum f{\"u}r Hochschulforschung, -praxis und -politik},
  volume    = {55},
  journal   = {Das Hochschulwesen : HSW ; Forum f{\"u}r Hochschulforschung, -praxis und -politik},
  number    = {5},
  issn      = {0018-2974},
  pages     = {144 -- 147},
  year      = {2007},
  language  = {de}
}
@inproceedings{WellmerChenBraunetal.2007,
  author    = {Wellmer, Georg and Chen, B.-H. and Braun, Carsten and Ballmann, Josef},
  title     = {Numerical prediction of aeroelastic effects on twin-sting-rig mounted models for rear fuselage and empennage flow investigation in transonic windtunnel},
  series = {Proceedings / IFASD 2007, CEAS/AIAA/KTH International Forum on Aeroelasticity and Structural Dynamics, June 18 - 21, 2007, Stockholm, Sweden},
  booktitle = {Proceedings / IFASD 2007, CEAS/AIAA/KTH International Forum on Aeroelasticity and Structural Dynamics, June 18 - 21, 2007, Stockholm, Sweden},
  publisher = {KTH},
  address   = {Stockholm},
  organization    = {Confederation of European Aerospace Societies ; American Institute of Aeronautics and Astronautics, Reston, Va. ; Kungliga Tekniska H{\"o}gskolan, Stockholm},
  pages     = {1 CD-ROM},
  year      = {2007},
  language  = {en}
}
@book{Ley2008,
  author    = {Ley, Wilfried},
  title     = {Handbuch der Raumfahrttechnik / Ley, Wilfried ; Wittmann, Klaus ; Hallmann, Willi [Hrsg.]},
  publisher = {Hanser},
  address   = {M{\"u}nchen},
  isbn      = {978-3-446-41185-2},
  pages     = {814 S. : zahlr. Ill., graph. Darst.},
  year      = {2008},
  language  = {de}
}
@book{Funke2008,
  author    = {Funke, Harald},
  title     = {Optimierung und Miniaturisierung der Mikro-Misch-Diffusionsverbrennung von Wasserstoff zur potentiellen Anwendung in einer Ultra-Gasturbine. Schlussbericht.},
  publisher = {Fachhochschule Aachen},
  address   = {Aachen},
  pages     = {85 S.},
  year      = {2008},
  language  = {de}
}
@article{FunkeRoennaRobinson2008,
  author    = {Funke, Harald and R{\"o}nna, Uwe and Robinson, A. E.},
  title     = {Development and testing of a 10 kW diffusive micromix combustor for hydrogen-fuelled μ-scale gas turbines},
  series = {Proceedings of ASME Turbo Expo 2008: Power for Land, Sea and Air ; GT2008 ; June 9-13, 2008, Berlin, Germany},
  journal   = {Proceedings of ASME Turbo Expo 2008: Power for Land, Sea and Air ; GT2008 ; June 9-13, 2008, Berlin, Germany},
  publisher = {ASME},
  address   = {New York, NY},
  pages     = {1 -- 8},
  year      = {2008},
  language  = {en}
}
@article{HavermannHaertigReyetal.2008,
  author    = {Havermann, Marc and Haertig, J. and Rey, C. and George, A.},
  title     = {PIV Measurements in Shock Tunnels and Shock Tubes / Havermann, M. ; Haertig, J. ; Rey, C. ; George, A.},
  series = {Particle Image Velocimetry : New Developments and Recent Applications},
  journal   = {Particle Image Velocimetry : New Developments and Recent Applications},
  publisher = {Springer},
  address   = {Berlin},
  isbn      = {978-3-540-73528-1},
  pages     = {429 -- 442},
  year      = {2008},
  language  = {en}
}
@article{HavermannSeilerGeorgesetal.2008,
  author    = {Havermann, Marc and Seiler, F. and Georges, A. and Srulijes, J.},
  title     = {Progress in Doppler picture velocimetry (DPV) / Seiler, F. ; George, A. ; Srulijes, J. ; Havermann, M.},
  series = {Experiments in Fluids. 44 (2008), H. 3},
  journal   = {Experiments in Fluids. 44 (2008), H. 3},
  publisher = {-},
  isbn      = {1432-1114},
  pages     = {389 -- 395},
  year      = {2008},
  language  = {en}
}
@inproceedings{ChristenBarteltKowalskietal.2008,
  author    = {Christen, Marc and Bartelt, Perry and Kowalski, Julia and Stoffel, Lukus},
  title     = {Calculation of dense snow avalanches in three-dimensional terrain with the numerical simulation programm RAMMS},
  series = {Proceedings ISSW 2008 ; International Snow Science Workshop. Whistler 2008},
  booktitle = {Proceedings ISSW 2008 ; International Snow Science Workshop. Whistler 2008},
  pages     = {709 -- 716},
  year      = {2008},
  abstract  = {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.},
  language  = {en}
}
@inproceedings{KowalskiMcElwaine2008,
  author    = {Kowalski, Julia and McElwaine, J.},
  title     = {Two-phase debris flow modeling},
  series = {Geophysical Research Abstracts},
  booktitle = {Geophysical Research Abstracts},
  year      = {2008},
  language  = {en}
}
@article{Kowalski2008,
  author    = {Kowalski, Julia},
  title     = {Mathematische Murgangmodellierung},
  series = {Newsletter Naturgefahren},
  volume    = {2008},
  journal   = {Newsletter Naturgefahren},
  number    = {2},
  organization    = {Eidgen{\"o}ssisches Institut f{\"u}r Schnee-und Lawinenforschung SLF},
  pages     = {4 -- 5},
  year      = {2008},
  language  = {de}
}
@phdthesis{Kowalski2008,
  author    = {Kowalski, Julia},
  title     = {Two-phase Modeling of Debris Flows},
  publisher = {Mensch und Buch},
  address   = {Berlin},
  isbn      = {978-3-86664-524-0},
  pages     = {148},
  year      = {2008},
  language  = {en}
}
@article{TrillaGrossenRobinsonetal.2008,
  author    = {Trilla, Joan and Grossen, J{\"u}rgen and Robinson, Alexander and Funke, Harald and Bosschaerts, Walter and Hendrick, Patrick},
  title     = {Development of a hydrogen combustion chamber for an ultra micro gas turbine},
  series = {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},
  journal   = {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},
  pages     = {101 -- 104},
  year      = {2008},
  language  = {en}
}
@article{RobinsonFunkeHendricketal.2008,
  author    = {Robinson, A. E. and Funke, Harald and Hendrick, P. and Recker, E. and Peirs, J.},
  title     = {Development of a hydrogen fuelled 1 kW ultra micro gas turbine with special respect to designing, testing and mapping of the µ-scale combustor},
  series = {IEEE International Conference on Sustainable Energy Technologies, 2008 : ICSET 2008 ; Singapore, 24 - 27 Nov. 2008.},
  journal   = {IEEE International Conference on Sustainable Energy Technologies, 2008 : ICSET 2008 ; Singapore, 24 - 27 Nov. 2008.},
  publisher = {IEEE},
  address   = {Piscataway, NJ},
  isbn      = {978-1-4244-1887-9},
  pages     = {656 -- 660},
  year      = {2008},
  language  = {en}
}
@book{WittmannLeyHallmann2008,
  author    = {Wittmann, Klaus and Ley, Wilfried [Hrsg.] and Hallmann, Willi [Hrsg.]},
  title     = {Handbuch der Raumfahrttechnik : mit 128 Tabellen / Wilfried Ley; Klaus Wittmann; Willi Hallmann (Hrsg.) 3., v{\"o}llig neu bearb. und erw. Aufl.},
  publisher = {Hanser},
  address   = {M{\"u}nchen},
  isbn      = {978-3-446-41185-2},
  pages     = {814 S. : Ill., graph. Darst.},
  year      = {2008},
  language  = {de}
}
@book{EschAppelHoepke2008,
  author    = {Esch, Thomas and Appel, Wolfgang and H{\"o}pke, Friedrich},
  title     = {Nutzfahrzeugtechnik : Grundlagen, Systeme, Komponenten ; mit 35 Tabellen / Appel, Wolfgang ; H{\"o}pke, Friedrich ... Esch, Thomas [u.a.] 5., vollst. {\"u}berarb. Aufl.},
  publisher = {Vieweg + Teubner},
  address   = {Wiesbaden},
  isbn      = {978-3-8348-0374-0},
  pages     = {XXVIII, 509 S. : zahlr. Ill. und graph. Darst.},
  year      = {2008},
  language  = {de}
}
@book{Esch2008,
  author    = {Esch, Thomas},
  title     = {Verbrennungstechnik : Vorlesungsumdruck. 7. Aufl.},
  publisher = {Fachhochschule Aachen, Lehr- und Forschungsgebiet Thermodynamik und Verbrennungstechnik},
  address   = {Aachen},
  pages     = {Getr. Z{\"a}hlung : Ill. und graph. Darst.},
  year      = {2008},
  language  = {de}
}
@article{DachwaldSeboldtLoebetal.2008,
  author    = {Dachwald, Bernd and Seboldt, Wolfgang and Loeb, H. W. and Schartner, Karl-Heinz},
  title     = {Main Belt Asteroid Sample Return Mission Using Solar Electric Propulsion},
  series = {Acta Astronautica. 63 (2008), H. 1-4},
  journal   = {Acta Astronautica. 63 (2008), H. 1-4},
  isbn      = {0094-5765},
  pages     = {91 -- 101},
  year      = {2008},
  language  = {en}
}
@inproceedings{NowackRoethBuehrigPolaczeketal.2008,
  author    = {Nowack, N. and R{\"o}th, Thilo and B{\"u}hrig-Polaczek, A. and Klaus, G.},
  title     = {Advanced Sheet Metal Components Reinforced by Light Metal Cast Structures},
  series = {Aluminium alloys : their physical and mechanical properties ; [proceedings of the 11th International Conference on Aluminium Alloys, 22 - 26 Sept. 2008, Aachen, Germany ; ICAA 11]},
  booktitle = {Aluminium alloys : their physical and mechanical properties ; [proceedings of the 11th International Conference on Aluminium Alloys, 22 - 26 Sept. 2008, Aachen, Germany ; ICAA 11]},
  number    = {2},
  editor    = {Hirsch, J{\"u}rgen},
  isbn      = {978-3-527-32367-8},
  pages     = {2374 -- 2381},
  year      = {2008},
  language  = {en}
}
@article{DachwaldSeboldtLaemmerzahl2008,
  author    = {Dachwald, Bernd and Seboldt, Wolfgang and L{\"a}mmerzahl, W.},
  title     = {Solar Sail Propulsion: An Enabling Technology for Fundamental Physics Missions},
  series = {Lasers, Clocks and Drag Free Control : Exploration of Relativistic Gravity in Space / by Hansj{\"o}rg Dittus ..., eds. - ( Astrophysics and Space Science Library ; 349)},
  journal   = {Lasers, Clocks and Drag Free Control : Exploration of Relativistic Gravity in Space / by Hansj{\"o}rg Dittus ..., eds. - ( Astrophysics and Space Science Library ; 349)},
  publisher = {Springer},
  address   = {Berlin [u.a.]},
  isbn      = {978-3-540-34376-9},
  pages     = {379 -- 398},
  year      = {2008},
  language  = {en}
}
@article{DachwaldSeboldt2008,
  author    = {Dachwald, Bernd and Seboldt, Wolfgang},
  title     = {Solar Sails — Propellantless Propulsion for Near- and Medium-Term Deep-Space Missions / W. Seboldt ; B. Dachwald},
  series = {Advanced Propulsion Systems and Technologies, Today to 2020 / Claudio Bruno (ed.) ... - (Progress in Astronautics and Aeronautics Series ; 223)},
  journal   = {Advanced Propulsion Systems and Technologies, Today to 2020 / Claudio Bruno (ed.) ... - (Progress in Astronautics and Aeronautics Series ; 223)},
  publisher = {AIAA},
  address   = {Reston, Va.},
  isbn      = {978-1-56347-929-8},
  pages     = {460 S.},
  year      = {2008},
  language  = {en}
}
@article{PolaczekHenn2008,
  author    = {Polaczek, Christa and Henn, Gudrun},
  title     = {Gute Vorkenntnisse verk{\"u}rzen die Studienzeit},
  series = {Mathematikinformation : eine Zeitschrift von Begabtenf{\"o}rderung Mathematik e.V.},
  volume    = {2008},
  journal   = {Mathematikinformation : eine Zeitschrift von Begabtenf{\"o}rderung Mathematik e.V.},
  number    = {49},
  publisher = {Begabtenf{\"o}rderung Mathematik},
  address   = {Neubiberg},
  issn      = {1612-9156},
  pages     = {46 -- 50},
  year      = {2008},
  language  = {de}
}
@article{RobinsonFunkeWagemakersetal.2009,
  author    = {Robinson, A. E. and Funke, Harald and Wagemakers, R. and Grossen, J. and Bosschaerts, W. and Hendrick, P.},
  title     = {Numerical and Experimental Investigation of a Micromix Combustor for a Hydrogen Fuelled μ-Scale Gas Turbine},
  series = {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},
  journal   = {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},
  publisher = {ASME},
  address   = {New York, NY},
  isbn      = {9780791848869},
  pages     = {253 -- 262},
  year      = {2009},
  language  = {en}
}
@article{RoethNowackOberschelpetal.2009,
  author    = {R{\"o}th, Thilo and Nowack, Niels and Oberschelp, Christian and Lao, Bin},
  title     = {Gute Perspektiven f{\"u}r Stahl-Alumnium-Hybride im Automotivebereich / Nowack, Niels ; Oberschelp, Christian ; Lao, Bin ; Klaus, Gerald ; B{\"u}hrig-Polaczek, Andreas ; R{\"o}th, Thilo},
  series = {Giesserei : die Zeitschrift f{\"u}r Technik, Innovation und Management. 96 (2009), H. 5},
  journal   = {Giesserei : die Zeitschrift f{\"u}r Technik, Innovation und Management. 96 (2009), H. 5},
  isbn      = {0016-9765},
  pages     = {110 -- 123},
  year      = {2009},
  language  = {de}
}
@article{RoethKernKirchneretal.2009,
  author    = {R{\"o}th, Thilo and Kern, Daniel and Kirchner, Karsten and Vietor, Thomas},
  title     = {Flexbody : Baukastensystem f{\"u}r Karosseriestrukturen / Kern, Daniel ; R{\"o}th, Thilo ; Kirchner, Karsten ; Vietor, Thomas},
  series = {Mobiles : Fachzeitschrift f{\"u}r Konstrukteure. 35 (2009), H. 2009/2010},
  journal   = {Mobiles : Fachzeitschrift f{\"u}r Konstrukteure. 35 (2009), H. 2009/2010},
  publisher = {Hochsch. f{\"u}r Angewandte Wiss.},
  address   = {Hamburg},
  pages     = {73 -- 75},
  year      = {2009},
  language  = {de}
}
@article{PichlerGeorgeSeileretal.2009,
  author    = {Pichler, A. and George, A. and Seiler, F. and Srulijes, J. and Havermann, Marc},
  title     = {Doppler Picture Velocimetry (DPV) applied to hypersonics},
  series = {Shock Waves [Elektronische Ressource] : 26th International Symposium on Shock Waves, Volume 1 / edited by Klaus Hannemann, Friedrich Seiler},
  journal   = {Shock Waves [Elektronische Ressource] : 26th International Symposium on Shock Waves, Volume 1 / edited by Klaus Hannemann, Friedrich Seiler},
  publisher = {Springer},
  address   = {Berlin},
  isbn      = {978-3-540-85168-4},
  pages     = {503 -- 508},
  year      = {2009},
  language  = {en}
}
@article{FischerKowalskiPudasainietal.2009,
  author    = {Fischer, Jan-Thomas and Kowalski, Julia and Pudasaini, Shiva P. and Miller, S. A.},
  title     = {Dynamic Avalanche Modeling in Natural Terrain},
  series = {International Snow Science Workshop, Davos 2009, Proceedings ; Proc. ISSW 2009},
  journal   = {International Snow Science Workshop, Davos 2009, Proceedings ; Proc. ISSW 2009},
  pages     = {448 -- 452},
  year      = {2009},
  abstract  = {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.},
  language  = {en}
}
@inproceedings{BoernerFunkeHendricketal.2009,
  author    = {B{\"o}rner, Sebastian and Funke, Harald and Hendrick, P. and Recker, E.},
  title     = {LES of Jets In Cross-Flow and Application to the "Micromix" Hydrogen Combustion},
  series = {XIX International Symposium on Air Breathing Engines 2009 (ISABE 2009) : Proceedings of a meeting held 7-11 September 2009, Montreal, Canada},
  booktitle = {XIX International Symposium on Air Breathing Engines 2009 (ISABE 2009) : Proceedings of a meeting held 7-11 September 2009, Montreal, Canada},
  isbn      = {9781615676064},
  pages     = {1555 -- 1561},
  year      = {2009},
  language  = {en}
}
@inproceedings{KowalskiBugnion2009,
  author    = {Kowalski, Julia and Bugnion, Louis},
  title     = {An extended shallow flow theory for natural debris flows},
  volume    = {41},
  number    = {7},
  pages     = {609 -- 609},
  year      = {2009},
  language  = {de}
}
@book{LeyWittmannHallmann2009,
  author    = {Ley, Wilfried and Wittmann, Klaus and Hallmann, Willi},
  title     = {Handbook of space technology},
  publisher = {Wiley},
  address   = {Chichester},
  isbn      = {978-0-470-69739-9},
  pages     = {XIII, 882 S. : Ill., graph. Darst.},
  year      = {2009},
  language  = {en}
}
@article{WilsonBlome2009,
  author    = {Wilson, T. L. and Blome, Hans-Joachim},
  title     = {The Pioneer anomaly and a rotating G{\"o}del universe},
  series = {Advances in Space Research},
  volume    = {44},
  journal   = {Advances in Space Research},
  number    = {11},
  isbn      = {0273-1177},
  pages     = {1345 -- 1353},
  year      = {2009},
  language  = {en}
}
@inproceedings{RoethStark2009,
  author    = {R{\"o}th, Thilo and Stark, R.},
  title     = {Die Rolle der virtuellen Produktentstehung bei der Integration von Karosseriesystemen},
  series = {Karosseriekongress Systemintegration in der Karosserietechnik : 17. und 18. M{\"a}rz 2009 in Baden-Baden / Kongressleitung: Reiner Stark},
  booktitle = {Karosseriekongress Systemintegration in der Karosserietechnik : 17. und 18. M{\"a}rz 2009 in Baden-Baden / Kongressleitung: Reiner Stark},
  publisher = {VDI-Wissensforum},
  address   = {D{\"u}sseldorf},
  isbn      = {978-3-9812624-4-5},
  pages     = {175 S. : zahlr. Ill., graph. Darst.},
  year      = {2009},
  language  = {de}
}
@book{Esch2009,
  author    = {Esch, Thomas},
  title     = {Raumfahrtantriebe. 7. Aufl., [Umdruck]},
  publisher = {Fachhochschule Aachen, Lehr- und Forschungsgebiet Thermodynamik und Verbrennungstechnik},
  address   = {Aachen},
  pages     = {Getr. Z{\"a}hlung : Ill. und graph. Darst.},
  year      = {2009},
  language  = {de}
}
@inproceedings{DachwaldOhndorfSpurmannetal.2009,
  author    = {Dachwald, Bernd and Ohndorf, Andreas and Spurmann, J. and Loeb, H. W. and Schartner, Karl-Heinz and Seboldt, Wolfgang},
  title     = {Mission design for a SEP mission to saturn},
  series = {60th International Astronautical Congress 2009 (IAC 2009)},
  booktitle = {60th International Astronautical Congress 2009 (IAC 2009)},
  publisher = {Curran Associates, Inc.},
  address   = {Red Hook, NY},
  isbn      = {978-1-61567-908-9},
  pages     = {11 Seiten},
  year      = {2009},
  abstract  = {Within ESA's Cosmic Vision 2015-2025 plan, a mission to explore the Saturnian System, with special emphasis on its two moons Titan and Enceladus, was selected for study, termed TANDEM (Titan and Enceladus Mission). In this paper, we describe an optimized mission design for a TANDEM-derived solar electric propulsion (SEP) mission. We have chosen the SEP mission scenario for the interplanetary transfer of the TANDEM spacecraft because all feasible gravity assist sequences for a chemical transfer between 2015 and 2025 result in long flight times of about nine years. Our SEP system is based on the German RIT ion engine. For our optimized mission design, we have extensively explored the SEP parameter space (specific impulse, thrust level, power level) and have calculated an optimal interplanetary trajectory for each setting. In contrast to the original TANDEM mission concept, which intends to use two launch vehicles and an all-chemical transfer, our SEP mission design requires only a single Ariane 5 ECA launch for the same payload mass. Without gravity assist, it yields a faster and more flexible transfer with a fight time of less than seven years, and an increased payload ratio. Our mission design proves thereby the capability of SEP even for missions into the outer solar system.},
  language  = {en}
}
@inproceedings{DachwaldWurm2009,
  author    = {Dachwald, Bernd and Wurm, P.},
  title     = {Design concept and modeling of an advanced solar photon thruster},
  series = {Advances in the Astronautical Sciences},
  booktitle = {Advances in the Astronautical Sciences},
  publisher = {American Astronautical Society},
  address   = {San Diego, Calif.},
  isbn      = {978-087703554-1},
  issn      = {00653438},
  pages     = {723 -- 740},
  year      = {2009},
  abstract  = {The so-called "compound solar sail", also known as "Solar Photon Thruster" (SPT), holds the potential of providing significant performance advantages over the flat solar sail. Previous SPT design concepts, however, do not consider shadowing effects and multiple reflections of highly concentrated solar radiation that would inevitably destroy the gossamer sail film. In this paper, we propose a novel advanced SPT (ASPT) design concept that does not suffer from these oversimplifications. We present the equations that describe the thrust force acting on such a sail system and compare its performance with respect to the conventional flat solar sail.},
  language  = {en}
}
@incollection{ReimerWellmerBraunetal.2009,
  author    = {Reimer, Lars and Wellmer, Georg and Braun, Carsten and Ballmann, Josef},
  title     = {Computational methods for aero-structural analysis and optimisation of aircrafts based on reduced-order structural models},
  series = {MEGADESIGN and MegaOpt - German initiatives for aerodynamic simulation and optimization in aircraft design. Results of the closing symposium of the MEGADESIGN and MegaOpt projects, Braunschweig, Germany, 23 - 24 May, 2007 / Norbert Kroll ... (Eds.) Notes on numerical fluid mechanics and multidisciplinary design. Vol. 107},
  booktitle = {MEGADESIGN and MegaOpt - German initiatives for aerodynamic simulation and optimization in aircraft design. Results of the closing symposium of the MEGADESIGN and MegaOpt projects, Braunschweig, Germany, 23 - 24 May, 2007 / Norbert Kroll ... (Eds.) Notes on numerical fluid mechanics and multidisciplinary design. Vol. 107},
  publisher = {Springer},
  address   = {Berlin},
  isbn      = {978-3-642-04092-4},
  pages     = {135 -- 150},
  year      = {2009},
  abstract  = {In this part of the MEGADESIGN project, aeroelastic effects are introduced into the aerodynamic analysis of aircrafts by coupling DLR's flow solvers TAU and FLOWer to a Timoshenko-beam solver. The emerging aeroelastic solvers and a method for the automatic identification of Timoshenko-beam models for wing-box structures were integrated into a simulation environment enabling the combined optimisation of aerodynamic wing shape and structure.},
  language  = {en}
}
@inproceedings{SpurmannOhndorfDachwaldetal.2009,
  author    = {Spurmann, J{\"o}rn and Ohndorf, Andreas and Dachwald, Bernd and Seboldt, Wolfgang and L{\"o}b, Horst and Schartner, Karl-Heinz},
  title     = {Interplanetary trajectory optimization for a sep mission to Saturn},
  series = {60th International Astronautical Congress 2009},
  booktitle = {60th International Astronautical Congress 2009},
  isbn      = {9781615679089},
  pages     = {5234 -- 5248},
  year      = {2009},
  abstract  = {The recently proposed NASA and ESA missions to Saturn and Jupiter pose difficult tasks to mission designers because chemical propulsion scenarios are not capable of transferring heavy spacecraft into the outer solar system without the use of gravity assists. Thus our developed mission scenario based on the joint NASA/ESA Titan Saturn System Mission baselines solar electric propulsion to improve mission flexibility and transfer time. For the calculation of near-globally optimal low-thrust trajectories, we have used a method called Evolutionary Neurocontrol, which is implemented in the low-thrust trajectory optimization software InTrance. The studied solar electric propulsion scenario covers trajectory optimization of the interplanetary transfer including variations of the spacecraft's thrust level, the thrust unit's specific impulse and the solar power generator power level. Additionally developed software extensions enabled trajectory optimization with launcher-provided hyperbolic excess energy, a complex solar power generator model and a variable specific impulse ion engine model. For the investigated mission scenario, Evolutionary Neurocontrol yields good optimization results, which also hold valid for the more elaborate spacecraft models. Compared to Cassini/Huygens, the best found solutions have faster transfer times and a higher mission flexibility in general.},
  language  = {en}
}
@article{DachwaldOhndorfGill2009,
  author    = {Dachwald, Bernd and Ohndorf, A. and Gill, E.},
  title     = {Optimization of low-thrust Earth-Moon transfers using evolutionary neurocontrol / Ohndorf, A. ; Dachwald, B. ; Gill, E.},
  series = {IEEE Congress on Evolutionary Computation, 2009. CEC '09.},
  journal   = {IEEE Congress on Evolutionary Computation, 2009. CEC '09.},
  isbn      = {978-1-4244-2958-5},
  pages     = {358 -- 364},
  year      = {2009},
  language  = {en}
}
@inproceedings{DachwaldWurm2009,
  author    = {Dachwald, Bernd and Wurm, P.},
  title     = {Mission analysis for an advanced solar photon thruster},
  series = {60th International Astronautical Congress 2009, IAC 2009},
  volume    = {8},
  booktitle = {60th International Astronautical Congress 2009, IAC 2009},
  publisher = {Elsevier},
  address   = {Amsterdam},
  isbn      = {978-161567908-9},
  pages     = {6838 -- 6851},
  year      = {2009},
  abstract  = {The so-called "compound solar sail", also known as "Solar Photon Thruster" (SPT), is a solar sail design concept, for which the two basic functions of the solar sail, namely light collection and thrust direction, are uncoupled. In this paper, we introduce a novel SPT concept, termed the Advanced Solar Photon Thruster (ASPT). This model does not suffer from the simplified assumptions that have been made for the analysis of compound solar sails in previous studies. We present the equations that describe the force, which acts on the ASPT. After a detailed design analysis, the performance of the ASPT with respect to the conventional flat solar sail (FSS) is investigated for three interplanetary mission scenarios: An Earth-Venus rendezvous, where the solar sail has to spiral towards the Sun, an Earth-Mars rendezvous, where the solar sail has to spiral away from the Sun, and an Earth-NEA rendezvous (to near-Earth asteroid 1996FG3), where a large orbital eccentricity change is required. The investigated solar sails have realistic near-term characteristic accelerations between 0.1 and 0.2mm/s2. Our results show that a SPT is not superior to the flat solar sail unless very idealistic assumptions are made.},
  language  = {en}
}
@article{DachwaldBallUlamecetal.2009,
  author    = {Dachwald, Bernd and Ball, Andrew J. and Ulamec, Stephan and Price, Michael E.},
  title     = {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.]},
  series = {Advances in Space Research. 43 (2009), H. 2},
  journal   = {Advances in Space Research. 43 (2009), H. 2},
  publisher = {Elsevier},
  address   = {Amsterdam},
  isbn      = {0273-1177},
  pages     = {317 -- 324},
  year      = {2009},
  language  = {en}
}
@inproceedings{SchartnerLoebDachwaldetal.2009,
  author    = {Schartner, Karl-Heinz and Loeb, H. W. and Dachwald, Bernd and Ohndorf, Andreas},
  title     = {Perspectives of electric propulsion for outer planetary and deep space missions},
  series = {European Planetary Science Congress 2009},
  booktitle = {European Planetary Science Congress 2009},
  pages     = {416 -- 416},
  year      = {2009},
  abstract  = {Solar-electric propulsion (SEP) is superior with respect to payload capacity, flight time and flexible launch window to the conventional interplanetary transfer method using chemical propulsion combined with gravity assists. This fact results from the large exhaust velocities of electric low-thrust propulsion and is favourable also for missions to the giant planets, Kuiper-belt objects and even for a heliopause probe (IHP) as shown in three studies by the authors funded by DLR. They dealt with a lander for Europa and a sample return mission from a mainbelt asteroid [1], with the TANDEM mission [2]; the third recent one investigates electric propulsion for the transfer to the edge of the solar system. All studies are based on triple-junction solar arrays, on rf-ion thrusters of the qualified RIT-22 type and they use the intelligent trajectory optimization program InTrance [3].},
  language  = {en}
}
@article{DachwaldCarnelliVasile2009,
  author    = {Dachwald, Bernd and Carnelli, Ian and Vasile, Massimiliano},
  title     = {Evolutionary Neurocontrol: A Novel Method for Low-Thrust Gravity-Assist Trajectory Optimization / Carnelli, Ian ; Dachwald, Bernd ; Vasile, Massimiliano},
  series = {Journal of guidance control and dynamics. 32 (2009), H. 2},
  journal   = {Journal of guidance control and dynamics. 32 (2009), H. 2},
  publisher = {AIAA},
  address   = {Reston, Va.},
  isbn      = {0731-5090},
  pages     = {616 -- 625},
  year      = {2009},
  language  = {en}
}
@inproceedings{GehlerOberBloebaumDachwald2009,
  author    = {Gehler, M. and Ober-Bl{\"o}baum, S. and Dachwald, Bernd},
  title     = {Application of discrete mechanics and optimal control to spacecraft in non-keplerian motion around small solar system bodies},
  series = {Procceedings of the 60th International Astronautical Congress},
  booktitle = {Procceedings of the 60th International Astronautical Congress},
  publisher = {Elsevier},
  address   = {Amsterdam},
  isbn      = {978-161567908-9},
  pages     = {1360 -- 1371},
  year      = {2009},
  abstract  = {Prolonged operations close to small solar system bodies require a sophisticated control logic to minimize propellant mass and maximize operational efficiency. A control logic based on Discrete Mechanics and Optimal Control (DMOC) is proposed and applied to both conventionally propelled and solar sail spacecraft operating at an arbitrarily shaped asteroid in the class of Itokawa. As an example, stand-off inertial hovering is considered, recently identified as a challenging part of the Marco Polo mission. The approach is easily extended to stand-off orbits. We show that DMOC is applicable to spacecraft control at small objects, in particular with regard to the fact that the changes in gravity are exploited by the algorithm to optimally control the spacecraft position. Furthermore, we provide some remarks on promising developments.},
  language  = {en}
}
@inproceedings{FunkeEschRoosen2009,
  author    = {Funke, Harald and Esch, Thomas and Roosen, Peter},
  title     = {Using motor gasoline for aircrafts - coping with growing bio-fuel-caused risks by understanding cause-effect relationship},
  series = {Fuels 2009 : mineral oil based and alternative fuels ; 7th international colloquium ; January 14 - 15, 2009},
  booktitle = {Fuels 2009 : mineral oil based and alternative fuels ; 7th international colloquium ; January 14 - 15, 2009},
  editor    = {Bartz, Wilfried J.},
  publisher = {Technische Akademie Esslingen (TAE)},
  address   = {Ostfildern},
  isbn      = {978-3-924813-75-8},
  pages     = {237 -- 244},
  year      = {2009},
  abstract  = {The utilisation of vehicle-oriented gasoline in general aviation is very desirable for both ecological and economical reasons, as well as for general considerations of availability. As of today vehicle fuels may be used if the respective engine and cell are certified for such an operation. For older planes a supplementary technical certificate is provided for gasoline mixtures with less than 1 \% v/v ethanol only, though. Larger admixtures of ethanol may lead to sudden engine malfunction and should be considered as considerable security risks. Major problems are caused by the partially ethanol non-withstanding materials, a necessarily changed stochiometric adjustment of the engine for varying ethanol shares and the tendency for phase separation in the presence of absorbed water. The concepts of the flexible fuel vehicles are only partially applicable in the view of air security.},
  language  = {en}
}