@article{BuehlerChristenKowalskietal.2011,
  author    = {B{\"u}hler, Yves and Christen, Marc and Kowalski, Julia and Bartelt, Perry},
  title     = {Sensitivity of snow avalanche simulations to digital elevation model quality and resolution},
  series = {Annals of Glaciology},
  volume    = {52},
  journal   = {Annals of Glaciology},
  number    = {58},
  publisher = {Cambridge University Press},
  address   = {Cambridge},
  isbn      = {1727-5644},
  pages     = {72 -- 80},
  year      = {2011},
  abstract  = {Digital elevation models (DEMs), represent the three-dimensional terrain and are the basic input for numerical snow avalanche dynamics simulations. DEMs can be acquired using topographic maps or remote-sensing technologies, such as photogrammetry or lidar. Depending on the acquisition technique, different spatial resolutions and qualities are achieved. However, there is a lack of studies that investigate the sensitivity of snow avalanche simulation algorithms to the quality and resolution of DEMs. Here, we perform calculations using the numerical avalance dynamics model RAMMS, varying the quality and spatial resolution of the underlying DEMs, while holding the simulation parameters constant. We study both channelized and open-terrain avalanche tracks with variable roughness. To quantify the variance of these simulations, we use well-documented large-scale avalanche events from Davos, Switzerland (winter 2007/08), and from our large-scale avalanche test site, Valĺee de la Sionne (winter 2005/06). We find that the DEM resolution and quality is critical for modeled flow paths, run-out distances, deposits, velocities and impact pressures. Although a spatial resolution of ~25 m is sufficient for large-scale avalanche modeling, the DEM datasets must be checked carefully for anomalies and artifacts before using them for dynamics calculations.},
  language  = {en}
}
@article{ScholzRomagnoliDachwaldetal.2011,
  author    = {Scholz, Christina and Romagnoli, Daniele and Dachwald, Bernd and Theil, Stephan},
  title     = {Performance analysis of an attitude control system for solar sails using sliding masses},
  series = {Advances in Space Research},
  volume    = {48},
  journal   = {Advances in Space Research},
  number    = {11},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0273-1177},
  pages     = {1822 -- 1835},
  year      = {2011},
  language  = {en}
}
@article{FunkeReckerBosschaertsetal.2011,
  author    = {Funke, Harald and Recker, E. and Bosschaerts, W. and Boonen, Q. and B{\"o}rner, Sebastian},
  title     = {Parametrical study of the „Micromix" hydrogen combustion principle},
  series = {10th International Symposium on Experimental and Computational Aerothermodynamics of Internal Flows, ISAIF10-049, Brussels, Belgium, 4-7 July 2011},
  journal   = {10th International Symposium on Experimental and Computational Aerothermodynamics of Internal Flows, ISAIF10-049, Brussels, Belgium, 4-7 July 2011},
  year      = {2011},
  language  = {en}
}
@incollection{FunkeBoernerHendricketal.2011,
  author    = {Funke, Harald and B{\"o}rner, Sebastian and Hendrick, P. and Recker, E.},
  title     = {Modification and testing of an engine and fuel control system for a hydrogen fuelled gas turbine},
  series = {Progress in Propulsion Physics. Vol. 2},
  booktitle = {Progress in Propulsion Physics. Vol. 2},
  publisher = {EDP Sciences},
  address   = {Les Ulis},
  isbn      = {978-2-7598-0673-7},
  pages     = {475 -- 486},
  year      = {2011},
  language  = {en}
}
@article{DachwaldWurm2011,
  author    = {Dachwald, Bernd and Wurm, Patrick},
  title     = {Mission analysis and performance comparison for an Advanced Solar Photon Thruster},
  series = {Advances in Space Research},
  volume    = {48},
  journal   = {Advances in Space Research},
  number    = {11},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0273-1177},
  pages     = {1858 -- 1868},
  year      = {2011},
  language  = {en}
}
@inproceedings{ThenentDahmann2011,
  author    = {Thenent, N. E. and Dahmann, Peter},
  title     = {Increasing aircraft design flexibility - The development of a hydrostatic transmission for gliders with self-launching capability},
  series = {Deutscher Luft- und Raumfahrtkongress 2011 : Bremen, 27. bis 29. September 2011 ; Tagungsband},
  booktitle = {Deutscher Luft- und Raumfahrtkongress 2011 : Bremen, 27. bis 29. September 2011 ; Tagungsband},
  publisher = {Dt. Gesellschaft f{\"u}r Luft- und Raumfahrt},
  address   = {Bonn},
  isbn      = {978-3-9321-8274-7},
  pages     = {865 -- 883},
  year      = {2011},
  language  = {en}
}
@inproceedings{DachwaldXuFeldmannetal.2011,
  author    = {Dachwald, Bernd and Xu, Changsheng and Feldmann, Marco and Plescher, Engelbert},
  title     = {IceMole : Development of a novel subsurface ice probe and testing of the first prototype on the Morteratsch Glacier},
  series = {EGU General Assembly 2011 Vienna | Austria | 03 - 08 April 2011},
  booktitle = {EGU General Assembly 2011 Vienna | Austria | 03 - 08 April 2011},
  year      = {2011},
  abstract  = {We present the novel concept of a combined drilling and melting probe for subsurface ice research. This probe, named "IceMole", is currently developed, built, and tested at the FH Aachen University of Applied Sciences' Astronautical Laboratory. Here, we describe its first prototype design and report the results of its field tests on the Swiss Morteratsch glacier. Although the IceMole design is currently adapted to terrestrial glaciers and ice shields, it may later be modified for the subsurface in-situ investigation of extraterrestrial ice, e.g., on Mars, Europa, and Enceladus. If life exists on those bodies, it may be present in the ice (as life can also be found in the deep ice of Earth).},
  language  = {en}
}
@inproceedings{ThenentDahmann2011,
  author    = {Thenent, N. E. and Dahmann, Peter},
  title     = {Hydrostatic propeller drive},
  series = {Proceedings of the conference : 18 - 20 May, 2011 Tampere, Finland / the Twelth Scandinavian International Conference on Fluid Power, SICFP'11. Ed.: Harri Sairiala ... Vol. 1},
  booktitle = {Proceedings of the conference : 18 - 20 May, 2011 Tampere, Finland / the Twelth Scandinavian International Conference on Fluid Power, SICFP'11. Ed.: Harri Sairiala ... Vol. 1},
  address   = {Tampere},
  isbn      = {978-952-15-2517-9},
  pages     = {217 -- 227},
  year      = {2011},
  language  = {en}
}
@inproceedings{OlaruKowalskiSethietal.2011,
  author    = {Olaru, Alexandra Maria and Kowalski, Julia and Sethi, Vaishali and Bl{\"u}mich, Bernhard},
  title     = {Fluid Transport in Porous Media probed by Relaxation-Exchange NMR},
  series = {2011 Fall Meeting, AGU, San Francisco, Calif., 5-9 Dec.},
  booktitle = {2011 Fall Meeting, AGU, San Francisco, Calif., 5-9 Dec.},
  year      = {2011},
  language  = {en}
}
@inproceedings{OhndorfDachwaldSeboldtetal.2011,
  author    = {Ohndorf, Andreas and Dachwald, Bernd and Seboldt, Wolfgang and Schartner, Karl-Heinz},
  title     = {Flight times to the heliopause using a combination of solar and radioisotope electric propulsion},
  series = {32nd International Electric Propulsion Conference},
  booktitle = {32nd International Electric Propulsion Conference},
  pages     = {1 -- 12},
  year      = {2011},
  abstract  = {We investigate the interplanetary flight of a low-thrust space probe to the heliopause,located at a distance of about 200 AU from the Sun. Our goal was to reach this distance within the 25 years postulated by ESA for such a mission (which is less ambitious than the 15-year goal set by NASA). Contrary to solar sail concepts and combinations of allistic and electrically propelled flight legs, we have investigated whether the set flight time limit could also be kept with a combination of solar-electric propulsion and a second, RTG-powered upper stage. The used ion engine type was the RIT-22 for the first stage and the RIT-10 for the second stage. Trajectory optimization was carried out with the low-thrust optimization program InTrance, which implements the method of Evolutionary Neurocontrol,using Artificial Neural Networks for spacecraft steering and Evolutionary Algorithms to optimize the Neural Networks' parameter set. Based on a parameter space study, in which the number of thrust units, the unit's specific impulse, and the relative size of the solar power generator were varied, we have chosen one configuration as reference. The transfer time of this reference configuration was 29.6 years and the fastest one, which is technically more challenging, still required 28.3 years. As all flight times of this parameter study were longer than 25 years, we further shortened the transfer time by applying a launcher-provided hyperbolic excess energy up to 49 km2/s2. The resulting minimal flight time for the reference configuration was then 27.8 years. The following, more precise optimization to a launch with the European Ariane 5 ECA rocket reduced the transfer time to 27.5 years. This is the fastest mission design of our study that is flexible enough to allow a launch every year. The inclusion of a fly-by at Jupiter finally resulted in a flight time of 23.8 years,which is below the set transfer-time limit. However, compared to the 27.5-year transfer,this mission design has a significantly reduced launch window and mission flexibility if the escape direction is restricted to the heliosphere's "nose".},
  language  = {en}
}