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 - 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 - Gerhardt, Hans Joachim A1 - Schönwald, J. T1 - Eine neue Brandsimulationsvorrichtung JF - vfdb-Zeitschrift. 51 (2002), H. 3 Y1 - 2002 SN - 0042-1804 SP - 91 EP - 93 ER - TY - JOUR A1 - Blome, Hans-Joachim T1 - Eine Reise an die Grenzen von Raum und Zeit. Wie die Raumfahrt unser Bild vom Kosmos erweitert. JF - DLR- Nachrichten. Mitteilungen des Deutschen Zentrums für Luft- und Raumfahrt. 90 (1998) Y1 - 1998 SN - 0937-0420 N1 - Sonderausgabe zum Tag der Raumfahrt 20.8.1998 SP - 20 EP - 29 ER - TY - JOUR A1 - Dahmann, Peter A1 - Mager, M. T1 - Einfluß der Zusammensetzung der abzuscheidenden Verschmutzung auf die Abscheideleistung von Hydraulikfiltern JF - Ölhydraulik und Pneumatik. 38 (1994), H. 4 Y1 - 1994 SN - 0341-2660 SP - 212 EP - 214 ER - TY - JOUR A1 - Mertens, Josef T1 - Einige herausragende Ergebnisse des Technologieprogramms "Reduktion des Aerodynamischen Widerstands (RaWid)" JF - DGLR-Jahrbuch 1999 Bd. 3 Y1 - 1999 N1 - DGLR-JT99-047 SP - 1461 EP - 1468 ER - TY - JOUR A1 - Peterson, Leif Arne A1 - Röth, Thilo A1 - Uibel, Thomas T1 - Einsatz von Holzwerkstoffen in Fahrzeugstrukturen JF - Bauen mit Holz Y1 - 2017 SN - 0005-6545 N1 - gedruckt in der Bereichsbibliothek Bayernallee IS - 3 SP - 32 EP - 38 PB - Bruderverlag CY - Köln ER - TY - JOUR A1 - Dahl, Günter A1 - Suttrop, F. T1 - Engine control and low-NO(x) combustion for hydrogen fuelled aircraft gas turbines JF - International Journal of Hydrogen Energy. 23 (1998), H. 8 Y1 - 1998 SN - 0360-3199 SP - 695 EP - 704 ER - TY - JOUR A1 - Havermann, Marc A1 - Seiler, F. A1 - George, A. A1 - Leopold, F. T1 - Enhanced Doppler Picture Velocimetry (DPV) for Planar Velocity Measurements in High-Speed Shock Tunnel Flow / Seiler, F. ; George, A. ; Leopold, F. ; Havermann, M. ; Srulijes, J. JF - 10th International Symposium on Flow Visualization : Kyōto, Japan, August 26 - 29, 2002 / sponsored by International Flow Visualization Society . [Chairman:] Toshio Kobayashi Y1 - 2002 SN - 4906497829 N1 - International Symposium on Flow Visualization ; (10 ; 2002.08.26-29 ; Kyōto) PB - Visualization Society of Japan CY - Kyoto ER - TY - JOUR A1 - Tekin, Nurettin A1 - Ashikaga, Mitsugu A1 - Horikawa, Atsushi A1 - Funke, Harald T1 - Enhancement of fuel flexibility of industrial gas turbines by development of innovative hydrogen combustion systems JF - Gas for energy N2 - For fuel flexibility enhancement hydrogen represents a possible alternative gas turbine fuel within future low emission power generation, in case of hydrogen production by the use of renewable energy sources such as wind energy or biomass. Kawasaki Heavy Industries, Ltd. (KHI) has research and development projects for future hydrogen society; production of hydrogen gas, refinement and liquefaction for transportation and storage, and utilization with gas turbine / gas engine for the generation of electricity. In the development of hydrogen gas turbines, a key technology is the stable and low NOx hydrogen combustion, especially Dry Low Emission (DLE) or Dry Low NOx (DLN) hydrogen combustion. Due to the large difference in the physical properties of hydrogen compared to other fuels such as natural gas, well established gas turbine combustion systems cannot be directly applied for DLE hydrogen combustion. Thus, the development of DLE hydrogen combustion technologies is an essential and challenging task for the future of hydrogen fueled gas turbines. The DLE Micro-Mix combustion principle for hydrogen fuel has been in development for many years to significantly reduce NOx emissions. This combustion principle is based on cross-flow mixing of air and gaseous hydrogen which reacts in multiple miniaturized “diffusion-type” flames. The major advantages of this combustion principle are the inherent safety against flashback and the low NOx-emissions due to a very short residence time of the reactants in the flame region of the micro-flames. Y1 - 2018 IS - 2 PB - Vulkan-Verlag CY - Essen ER - TY - JOUR A1 - Gerhardt, Hans Joachim A1 - Lieb, R.-D. T1 - Entrauchung komplexer Räumlichkeiten : Strategien und Steuerungen JF - Tür-Tor-Fenster-Report : Fachzeitschrift für die Technologien von Türen, Toren und Fenstern. 25 (2005), H. 3 Y1 - 2005 SN - 0724-7702 SP - 27 EP - 29 ER - TY - JOUR A1 - Gerhardt, Hans Joachim A1 - Schwarz, N. T1 - Entrauchung über Seitenwände JF - vfdb-Zeitschrift. 52 (2003), H. 1 Y1 - 2003 SN - 0042-1804 SP - 25 EP - 35 ER - TY - JOUR A1 - Gerhardt, Hans Joachim T1 - Entrauchungsnachweise. Kritische Diskussion von Methoden des Brandschutzingenieurwesens JF - vfdb-Zeitschrift. 50 (2001), H. 3 Y1 - 2001 SN - 0042-1804 SP - 99 EP - 104 ER - TY - JOUR A1 - Dachwald, Bernd T1 - Entwicklung sicherer und wartbarer Software für den Eurofighter JF - Soldat und Technik : Strategie und Technik, Sicherheit (1996) Y1 - 1996 SN - 0038-0989 SP - 663 EP - 668 ER - TY - JOUR A1 - Hoeveler, Bastian A1 - Janser, Frank A1 - Bindewald, Thorsten A1 - Gebhardt, Andreas T1 - Entwurf, Fertigung und Untersuchung eines Windkanalmodells eines innovativen, senkrechtstartenden Kleinflugzeuges JF - RTejournal - Forum für Rapid Technologie Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0009-2-42921 SN - 1614-0923 IS - 12 SP - 1 EP - 5 PB - Fachhochschule Aachen CY - Aachen 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 - 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 T1 - Evolutionary Neurocontrol: A Smart Method for Global Optimization of Low-Thrust Trajectories 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 ; AIAA/AAS Astrodynamics Specialist Conference and Exhibit <2004, Providence, RI> ; AIAA paper number: AIAA-2004-5405 PB - American Inst. of Aeronautics and Astronautics CY - Reston, Va. ER - TY - JOUR A1 - Olaru, Alexandra Maria A1 - Kowalski, Julia A1 - Sethi, Vaishali A1 - Blümich, Bernhard T1 - Exchange relaxometry of flow at small Péclet numbers in a glass bead pack JF - Journal of Magnetic Resonance (JMR) N2 - In this paper we consider low Péclet number flow in bead packs. A series of relaxation exchange experiments has been conducted and evaluated by ILT analysis. In the resulting correlation maps, we observed a collapse of the signal and a translation towards smaller relaxation times with increasing flow rates, as well as a signal tilt with respect to the diagonal. In the discussion of the phenomena we present a mathematical theory for relaxation exchange experiments that considers both diffusive and advective transport. We perform simulations based on this theory and discuss them with respect to the conducted experiments. KW - NMR exchange relaxometry KW - Low-field NMR Y1 - 2012 U6 - https://doi.org/10.1016/j.jmr.2012.04.015 SN - 1096-0856 VL - 220 SP - 32 EP - 44 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Haj Ayed, A. A1 - Kusterer, K. A1 - Funke, Harald A1 - Keinz, Jan A1 - Striegan, Constantin A1 - Bohn, D. T1 - Experimental and numerical investigations of the dry-low-NOx hydrogen micromix combustion chamber of an industrial gas turbine JF - Propulsion and power research Y1 - 2015 U6 - https://doi.org/10.1016/j.jppr.2015.07.005 SN - 2212-540X VL - Vol. 4 IS - Iss. 3 SP - 123 EP - 131 ER -