@inproceedings{SeboldtBlomeDachwaldetal.2004, author = {Seboldt, Wolfgang and Blome, Hans-Joachim and Dachwald, Bernd and Richter, Lutz}, title = {Proposal for an integrated European space exploration strategy}, series = {55th International Astronautical Congress of the International Astronautical Federation, the International Academy of Astronautics, and the International Institute of Space Law}, booktitle = {55th International Astronautical Congress of the International Astronautical Federation, the International Academy of Astronautics, and the International Institute of Space Law}, pages = {1 -- 10}, year = {2004}, abstract = {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.}, language = {en} } @article{BlomeSeboldtDachwaldetal.2004, author = {Blome, Hans-Joachim and Seboldt, Wolfgang and Dachwald, Bernd and Richter, Lutz}, title = {Proposal for an integrated European Space Exploration Study}, series = {Space Debris and Space Traffic Management Symposium 2004 : proceedings of the International Academy of Astronautics Space Debris and Space Traffic Management Symposium, held in conjunction with the 55th International Astronautical Congress (IAC), October 4 - 8, 2004, Vancouver, British Columbia, Canada / ed. by Joerg Bendisch}, journal = {Space Debris and Space Traffic Management Symposium 2004 : proceedings of the International Academy of Astronautics Space Debris and Space Traffic Management Symposium, held in conjunction with the 55th International Astronautical Congress (IAC), October 4 - 8, 2004, Vancouver, British Columbia, Canada / ed. by Joerg Bendisch}, publisher = {Univelt}, address = {San Diego, Calif.}, isbn = {0-87703-523-7}, pages = {XI, 432 S. : Ill., graph. Darst.}, year = {2004}, language = {en} } @inproceedings{HippeFingerGoettenetal.2020, author = {Hippe, Jonas and Finger, Felix and G{\"o}tten, Falk and Braun, Carsten}, title = {Propulsion System Qualification of a 25 kg VTOL-UAV: Hover Performance of Single and Coaxial Rotors and Wind-Tunnel Experiments on Cruise Propellers}, series = {Deutscher Luft- und Raumfahrtkongress - DLRK 2020}, booktitle = {Deutscher Luft- und Raumfahrtkongress - DLRK 2020}, year = {2020}, abstract = {This paper presents an approach for UAV propulsion system qualification and validation on the example of FH Aachen's 25 kg cargo UAV "PhoenAIX". Thrust and power consumption are the most important aspects of a propulsion system's layout. In the initial design phase, manufacturers' data has to be trusted, but the validation of components is an essential step in the design process. This process is presented in this paper. The vertical takeoff system is designed for efficient hover; therefore, performance under static conditions is paramount. Because an octo-copter layout with coaxial rotors is considered, the impact of this design choice is analyzed. Data on thrust, voltage stability, power consumption, rotational speed, and temperature development of motors and controllers are presented for different rotors. The fixed-wing propulsion system is designed for efficient cruise flight. At the same time, a certain static thrust has to be provided, as the aircraft needs to accelerate to cruise speed. As for the hover-system, data on different propellers is compared. The measurements were taken for static conditions, as well as for different inflow velocities, using the FH-Aachen's wind-tunnel.}, language = {en} } @inproceedings{SchopenShabaniEschetal.2022, author = {Schopen, Oliver and Shabani, Bahman and Esch, Thomas and Kemper, Hans and Shah, Neel}, title = {Quantitative evaluation of health management designs for fuel cell systems in transport vehicles}, series = {2nd UNITED-SAIG International Conference Proceedings}, booktitle = {2nd UNITED-SAIG International Conference Proceedings}, editor = {Rahim, S.A. and As'arry, A. and Zuhri, M.Y.M. and Harmin, M.Y. and Rezali, K.A.M. and Hairuddin, A.A.}, pages = {1 -- 3}, year = {2022}, abstract = {Focusing on transport vehicles, mainly with regard to aviation applications, this paper presents compilation and subsequent quantitative evaluation of methods aimed at building an optimum integrated health management solution for fuel cell systems. The methods are divided into two different main types and compiled in a related scheme. Furthermore, different methods are analysed and evaluated based on parameters specific to the aviation context of this study. Finally, the most suitable method for use in fuel cell health management systems is identified and its performance and suitability is quantified.}, language = {en} } @article{BlomeMashhoon1984, author = {Blome, Hans-Joachim and Mashhoon, B.}, title = {Quasi-normal oscillations of a Schwarzschild black hole}, series = {Physics Letters A. 100 (1984), H. 5}, journal = {Physics Letters A. 100 (1984), H. 5}, isbn = {0375-9601}, pages = {231 -- 234}, year = {1984}, language = {en} } @inproceedings{Dachwald2017, author = {Dachwald, Bernd}, title = {Radiation pressure force model for an ideal laser-enhanced solar sail}, series = {4th International Symposium on Solar Sailing}, booktitle = {4th International Symposium on Solar Sailing}, pages = {1 -- 5}, year = {2017}, abstract = {The concept of a laser-enhanced solar sail is introduced and the radiation pressure force model for an ideal laser-enhanced solar sail is derived. A laser-enhanced solar sail is a "traditional" solar sail that is, however, not solely propelled by solar radiation, but additionally by a laser beam that illuminates the sail. The additional laser radiation pressure increases the sail's propulsive force and can give, depending on the location of the laser source, more control authority over the direction of the solar sail's propulsive force vector. This way, laser-enhanced solar sails may augment already existing solar sail mission concepts and make novel mission concepts feasible.}, language = {en} } @article{ChristenKowalskiBartelt2010, author = {Christen, Marc and Kowalski, Julia and Bartelt, Perry}, title = {RAMMS: Numerical simulation of dense snow avalanches in three-dimensional terrain}, series = {Cold Regions Science and Technology}, volume = {63}, journal = {Cold Regions Science and Technology}, number = {1-2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1872-7441}, doi = {10.1016/j.coldregions.2010.04.005}, pages = {1 -- 14}, year = {2010}, abstract = {Numerical avalanche dynamics models have become an essential part of snow engineering. Coupled with field observations and historical records, they are especially helpful in understanding avalanche flow in complex terrain. However, their application poses several new challenges to avalanche engineers. A detailed understanding of the avalanche phenomena is required to construct hazard scenarios which involve the careful specification of initial conditions (release zone location and dimensions) and definition of appropriate friction parameters. The interpretation of simulation results requires an understanding of the numerical solution schemes and easy to use visualization tools. 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 accurate second-order numerical solution schemes. The model allows the specification of multiple release zones in three-dimensional terrain. Snow cover entrainment is considered. Furthermore, two different flow rheologies can be applied: the standard Voellmy-Salm (VS) approach or a random kinetic energy (RKE) model, which accounts for the random motion and inelastic interaction between snow granules. We present the governing differential equations, highlight some of the input and output features of RAMMS and then apply the models with entrainment to simulate two well-documented avalanche events recorded at the Vall{\´e}e de la Sionne test site.}, language = {en} } @article{GoettenHavermannBraunetal.2019, author = {G{\"o}tten, Falk and Havermann, Marc and Braun, Carsten and Gomez, Francisco and Bil, Cees}, title = {RANS Simulation Validation of a Small Sensor Turret for UAVs}, series = {Journal of Aerospace Engineering}, volume = {32}, journal = {Journal of Aerospace Engineering}, number = {5}, publisher = {ASCE}, address = {New York}, issn = {1943-5525}, doi = {10.1061/(ASCE)AS.1943-5525.0001055}, pages = {Article number 04019060}, year = {2019}, abstract = {Recent Unmanned Aerial Vehicle (UAV) design procedures rely on full aircraft steady-state Reynolds-Averaged-Navier-Stokes (RANS) analyses in early design stages. Small sensor turrets are included in such simulations, even though their aerodynamic properties show highly unsteady behavior. Very little is known about the effects of this approach on the simulation outcomes of small turrets. Therefore, the flow around a model turret at a Reynolds number of 47,400 is simulated with a steady-state RANS approach and compared to experimental data. Lift, drag, and surface pressure show good agreement with the experiment. The RANS model predicts the separation location too far downstream and shows a larger recirculation region aft of the body. Both characteristic arch and horseshoe vortex structures are visualized and qualitatively match the ones found by the experiment. The Reynolds number dependence of the drag coefficient follows the trend of a sphere within a distinct range. The outcomes indicate that a steady-state RANS model of a small sensor turret is able to give results that are useful for UAV engineering purposes but might not be suited for detailed insight into flow properties.}, language = {en} } @article{GerhardtKramer1992, author = {Gerhardt, Hans Joachim and Kramer, C.}, title = {Rauch- und W{\"a}rmeabzug - physikalische Grundlagen und Anwendungen}, series = {vfdb-Zeitschrift. 41 (1992), H. 2}, journal = {vfdb-Zeitschrift. 41 (1992), H. 2}, isbn = {0042-1804}, pages = {49 -- 54}, year = {1992}, language = {de} } @article{GerhardtKonrath2003, author = {Gerhardt, Hans Joachim and Konrath, Bernd}, title = {Rauchableitung in unterirdischen Verkehrsanlagen. M{\"o}glichkeiten und Hinweise zur Ausf{\"u}hrung.}, series = {vfdb-Zeitschrift. 52 (2003), H. 2}, journal = {vfdb-Zeitschrift. 52 (2003), H. 2}, isbn = {0042-1804}, pages = {59 -- 65}, year = {2003}, language = {de} } @article{Gerhardt2003, author = {Gerhardt, Hans Joachim}, title = {Rauchableitung und deren Effektivit{\"a}t in der 4. Elbtunnelr{\"o}hre}, series = {tunnel - Internationale Fachzeitschrift f{\"u}r unterirdisches Bauen (2003)}, journal = {tunnel - Internationale Fachzeitschrift f{\"u}r unterirdisches Bauen (2003)}, isbn = {0722-6241}, pages = {19 -- 28}, year = {2003}, language = {de} } @article{GerhardtSchmidtJung2002, author = {Gerhardt, Hans Joachim and Schmidt, G. and Jung, G.}, title = {Rauchversuch in einem Hochregallager}, series = {Bautechnik. 79 (2002), H. 6}, journal = {Bautechnik. 79 (2002), H. 6}, isbn = {0932-8351}, pages = {414 -- 417}, year = {2002}, language = {de} } @article{GerhardtJungSchmidt2002, author = {Gerhardt, Hans Joachim and Jung, G. and Schmidt, G.}, title = {Rauchversuch in einem Hochregallager. Die aerodynamisch wirksame {\"O}ffnungsfl{\"a}che f{\"u}r den Rauchabzug in Hochregallagern und ihr Einfluss auf die L{\"o}scharbeiten der Feuerwehr}, series = {vfdb-Zeitschrift. 51 (2002), H. 1}, journal = {vfdb-Zeitschrift. 51 (2002), H. 1}, isbn = {0042-1804}, pages = {21 -- 25}, year = {2002}, language = {de} } @article{Blome2000, author = {Blome, Hans-Joachim}, title = {Raumfahrt - zwischen Himmel und Erde}, series = {Technologien f{\"u}r das 21. Jahrhundert / [red. Leitung: Birgit Strackenbrock ...]}, journal = {Technologien f{\"u}r das 21. Jahrhundert / [red. Leitung: Birgit Strackenbrock ...]}, publisher = {Brockhaus}, address = {Leipzig [u.a.]}, isbn = {376537945X}, pages = {572 -- 679}, year = {2000}, language = {de} } @article{Blome2001, author = {Blome, Hans-Joachim}, title = {Raumfahrt und Exploration des Kosmos}, series = {Mensch, Leben, Schwerkraft, Kosmos : Perspektiven biowissenschaftlicher Weltraumforschung in Deutschland ; Berichtsband einer Klausurtagung vom 20. - 22.10.2000 in Stuttgart-Hohenheim/Birkach / Hinrich Rahmann ... (Hrsg.). [Ausgerichtet von der Deutschen Gesellschaft f{\"u}r Luft- und Raumfahrt medizin]}, journal = {Mensch, Leben, Schwerkraft, Kosmos : Perspektiven biowissenschaftlicher Weltraumforschung in Deutschland ; Berichtsband einer Klausurtagung vom 20. - 22.10.2000 in Stuttgart-Hohenheim/Birkach / Hinrich Rahmann ... (Hrsg.). [Ausgerichtet von der Deutschen Gesellschaft f{\"u}r Luft- und Raumfahrt medizin]}, publisher = {Heimbach}, address = {Stuttgart}, isbn = {3-935380-03-8}, pages = {80 -- 105}, year = {2001}, language = {de} } @book{Esch2005, author = {Esch, Thomas}, title = {Raumfahrtantriebe. - 6. Aufl., [Umdruck]}, publisher = {Fachhochschule Aachen, Lehr- und Forschungsgebiet Thermodynamik und Verbrennungstechnik}, address = {Aachen}, pages = {Getr. Z{\"a}hlung : Ill., graph. Darst.}, year = {2005}, 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} } @book{Ley1997, author = {Ley, Wilfried}, title = {Raumfahrtmissionen zur Erkundung des Sonnensystems : Gemeinschaftsveranstaltung der FH Aachen, der DGLR und des DLR / 10. Raumfahrt-Kolloquium an der Fachhochschule Aachen, 5. November 1997 / Ley, Wilfried [Hrsg.]}, publisher = {DGLR}, address = {Bonn}, isbn = {3-922010-99-7}, pages = {VIII, 251 S. : Ill., graph. Darst., 30 cm}, year = {1997}, language = {de} } @book{Ley1999, author = {Ley, Wilfried}, title = {Raumflugbetrieb : Gemeinschaftsveranstaltung der FH Aachen, der DGLR und der DLR / 12. Raumfahrt-Kolloquium an der Fachhochschule Aachen, 11. November 1999. / Ley Wilfried [Hrsg.]}, publisher = {DGLR}, address = {Bonn}, isbn = {3-932182-07-03}, pages = {VIII, 215 S. : zahlr. Ill., graph. Darst.}, year = {1999}, language = {de} } @article{Bullerschen1990, author = {Bullerschen, Klaus-Gerd}, title = {Rechenmodelle zur Stromverdr{\"a}ngung in ein- und mehrphasigen elektrischen Leitungen komplexer Geometrie}, series = {Elektrow{\"a}rme International, Edition B (Industrielle Elektrow{\"a}rme). 48 (1990), H. 4}, journal = {Elektrow{\"a}rme International, Edition B (Industrielle Elektrow{\"a}rme). 48 (1990), H. 4}, isbn = {0340-3521}, pages = {199 -- 210}, year = {1990}, language = {de} }