@article{RobinsonRoennaFunke2007, author = {Robinson, A. E. and R{\"o}nna, Uwe and Funke, Harald}, title = {Testing of a 10 kW diffusive micro-mix combustor for hydrogen-fuelled micro-scale gas turbines}, series = {International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications <7, 2007, Freiburg, Breisgau> ; PowerMEMS ; 7}, journal = {International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications <7, 2007, Freiburg, Breisgau> ; PowerMEMS ; 7}, pages = {225 -- 228}, year = {2007}, language = {en} } @book{HavermannSeilerGnemmietal.2001, author = {Havermann, Marc and Seiler, F. and Gnemmi, P. and Ende, H.}, title = {Study on lateral jet/cross flow interaction in the High Energy ISL Shock Tunnel : 23rd International Symposium on Shock Waves, Fort Worth/TX, USA, July 22 - 27, 2001 / Institut Franco-Allemand de Recherches de Saint-Louis. Seiler, F. ; Gnemmi, P. ; Ende, H. ; Havermann, M. ; Schwenzer, M....}, publisher = {ISL}, address = {Saint-Louis}, pages = {8 S. : Ill., graph. Darst.}, year = {2001}, language = {en} } @article{HavermannKainumaTakayama2005, author = {Havermann, Marc and Kainuma, M. and Takayama, K.}, title = {Influence of Physical and Geometrical Parameters on Vortex Rings Generated by a Shock Tube / Havermann, M. ; Kainuma, M. ; Takayama, K.}, series = {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}, journal = {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}, publisher = {ICT}, address = {Pfinztal}, pages = {getr. Z{\"a}hlung [ca. 600 S.]}, year = {2005}, language = {en} } @article{HavermannMoeglin2005, author = {Havermann, Marc and Moeglin, J.-P.}, title = {ISL's Research on Systems with Controlled Effects for Non-Lethal Applications / Moeglin, J.-P. ; Havermann, M. et al.}, series = {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}, journal = {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}, publisher = {ICT}, address = {Pfinztal}, pages = {getr. Z{\"a}hlung [ca. 600 S.]}, year = {2005}, language = {en} } @book{Havermann2005, author = {Havermann, Marc}, title = {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.}, publisher = {ISL}, address = {Saint-Louis}, pages = {6 S. : Ill., graph. Darst.}, year = {2005}, language = {en} } @article{HavermannHaertigReyetal.2001, author = {Havermann, Marc and Haertig, J. and Rey, C. and George, F.}, title = {PIV measurements in Mach 3.5 and 4.5 shock tunnel flow / Haertig, J. ; Havermann, M. ; Rey, C. ; George, F.}, publisher = {-}, year = {2001}, language = {en} } @article{Havermann2006, author = {Havermann, Marc}, title = {Systematic Shock Tube Experiments on Vortex Ring Generation and Propagation / Havermann, M. ; Kainuma, M. ; Takayama, K.}, series = {Shock waves : proceedings of the 25th International Symposium on Shock Waves-ISSW25, July 17 - 22, 2005, Bangalore, India / ed.: G. Jagadeesh}, journal = {Shock waves : proceedings of the 25th International Symposium on Shock Waves-ISSW25, July 17 - 22, 2005, Bangalore, India / ed.: G. Jagadeesh}, publisher = {Universities Pr.}, address = {Hyderabad}, isbn = {978-81-7371571-6}, pages = {1141 S.}, year = {2006}, language = {en} } @article{HavermannSalveTinetal.1994, author = {Havermann, Marc and Salve, M. de and Tin, G. del and Panella, B.}, title = {Experimental Study of the Temperature Field along a Density Lock / Salve, M. de ; Tin, G. del ; Panella, B. ; Sansoldo, D. ; Havermann, M.}, series = {Proceedings : International Conference on New Trends in Nuclear System Thermohydraulics, May 30th - June 2nd, 1994, Pisa / organized by Dipartimento di Costruzioni Meccaniche e Nucleari ... . Ed. by Francesco Oriolo}, journal = {Proceedings : International Conference on New Trends in Nuclear System Thermohydraulics, May 30th - June 2nd, 1994, Pisa / organized by Dipartimento di Costruzioni Meccaniche e Nucleari ... . Ed. by Francesco Oriolo}, publisher = {-}, address = {Pisa}, pages = {623 -- 630}, year = {1994}, language = {en} } @article{HavermannBeylich1998, author = {Havermann, Marc and Beylich, A. E.}, title = {Combined Measurement of Velocity, Temperature and Pressure in Compressible Gas Flows Using Laser-Induced Iodine Fluorescence / Havermann, M. ; Beylich, A. E.}, publisher = {-}, year = {1998}, language = {en} } @article{HavermannSeilerGeorgeetal.2002, author = {Havermann, Marc and Seiler, F. and George, A. and Leopold, F.}, title = {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.}, series = {10th International Symposium on Flow Visualization : Kyōto, Japan, August 26 - 29, 2002 / sponsored by International Flow Visualization Society . [Chairman:] Toshio Kobayashi}, journal = {10th International Symposium on Flow Visualization : Kyōto, Japan, August 26 - 29, 2002 / sponsored by International Flow Visualization Society . [Chairman:] Toshio Kobayashi}, publisher = {Visualization Society of Japan}, address = {Kyoto}, isbn = {4906497829}, year = {2002}, 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{KnoblochKowalskiBoesigeretal.2011, author = {Knobloch, V. and Kowalski, Julia and B{\"o}siger, P. and Kozerke, S.}, title = {Probabilistic Streamline Estimation from Accelerated Fourier Velocity Encoded Measurements}, series = {Proceedings of the 19th ISMRM International Society for Magnetic Resonance in Medicine}, booktitle = {Proceedings of the 19th ISMRM International Society for Magnetic Resonance in Medicine}, pages = {1215 -- 1215}, year = {2011}, language = {de} } @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} } @article{McArdellBarteltKowalski2007, author = {McArdell, Brian W. and Bartelt, Perry and Kowalski, Julia}, title = {Field observations of basal forces and fluid pore pressure in a debris flow}, series = {Geophysical Research Letters (GRL)}, volume = {34}, journal = {Geophysical Research Letters (GRL)}, number = {7}, isbn = {0094-8276}, year = {2007}, abstract = {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.}, language = {en} } @article{HeierliPurvesFelberetal.2004, author = {Heierli, Joachim and Purves, Ross S. and Felber, Andreas and Kowalski, Julia}, title = {Verification of nearest-neighbours interpretations in avalanche forecasting}, series = {Annals of Glaciology}, volume = {38}, journal = {Annals of Glaciology}, number = {1}, isbn = {1727-5644}, pages = {84 -- 88}, year = {2004}, abstract = {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.}, language = {en} } @misc{BaumgartnerWunderlichJaunichetal.2012, author = {Baumgartner, Thomas and Wunderlich, Florian and Jaunich, Arthur and Sato, Tomoo and Bundy, Georg and Grießmann, Nadine and Kowalski, Julia and Burghardt, Stefan and Hanebrink, J{\"o}rg}, title = {Lighting the way: Perspectives on the global lighting market}, edition = {2nd ed.}, address = {McKinsey}, pages = {58}, year = {2012}, language = {en} } @misc{Kowalski2010, type = {Master Thesis}, author = {Kowalski, Julia}, title = {Streamline estimation from sparsely sampled q-space Magnetic Resonance data}, year = {2010}, language = {de} } @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} } @article{KowalskiMcElwaine2013, author = {Kowalski, Julia and McElwaine, Jim N.}, title = {Shallow two-component gravity-driven flows with vertical variation}, series = {Journal of Fluid Mechanics}, volume = {714}, journal = {Journal of Fluid Mechanics}, publisher = {Cambridge Univ. Press}, address = {Cambridge}, isbn = {0022-1120}, pages = {434 -- 462}, year = {2013}, language = {en} } @article{OlaruKowalskiSethietal.2012, author = {Olaru, Alexandra Maria and Kowalski, Julia and Sethi, Vaishali and Bl{\"u}mich, Bernhard}, title = {Exchange relaxometry of flow at small P{\´e}clet numbers in a glass bead pack}, series = {Journal of Magnetic Resonance (JMR)}, volume = {220}, journal = {Journal of Magnetic Resonance (JMR)}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1096-0856}, doi = {10.1016/j.jmr.2012.04.015}, pages = {32 -- 44}, year = {2012}, abstract = {In this paper we consider low P{\´e}clet 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.}, language = {en} }