TY  - JOUR
A1  - Christen, Marc
A1  - Bartelt, Perry
A1  - Kowalski, Julia
T1  - Back calculation of the In den Arelen avalanche with RAMMS: Interpretation of model results
JF  - Annals of Glaciology
N2  - Two- and three-dimensional avalanche dynamics models are being increasingly used in hazard-mitigation studies. These models can provide improved and more accurate results for hazard mapping than the simple one-dimensional models presently used in practice. However, two- and three-dimensional models generate an extensive amount of output data, making the interpretation of simulation results more difficult. To perform a simulation in three-dimensional terrain, numerical models require a digital elevation model, specification of avalanche release areas (spatial extent and volume), selection of solution methods, finding an adequate calculation resolution and, finally, the choice of friction parameters. In this paper, the importance and difficulty of correctly setting up and analysing the results of a numerical avalanche dynamics simulation is discussed. We apply the two-dimensional simulation program RAMMS to the 1968 extreme avalanche event In den Arelen. We show the effect of model input variations on simulation results and the dangers and complexities in their interpretation.
KW  - avalanche
Y1  - 2010
SN  - 1727-5644
U6  - http://dx.doi.org/10.3189/172756410791386553
VL  - 51
IS  - 54
SP  - 161
EP  - 168
PB  - Cambridge University Press
CY  - Cambridge
ER  - 
TY  - CHAP
A1  - Havermann, Marc
A1  - Seiler, F.
A1  - Henning, P.
ED  - Dillmann, Andreas
ED  - Heller, Gerd
ED  - Klaas, Michael
ED  - Kreplin, Hans-Peter
ED  - Nitsche, Wolfgang
ED  - Schröder, Wolfgang
T1  - Shock Tunnel Experiments and CFD Simulation of Lateral Jet Interaction in Hypersonic Flows
T2  - New Results in Numerical and Experimental Fluid Mechanics VII; Contributions to the 16th STAB/DGLR Symposium Aachen, Germany 2008
Y1  - 2010
SN  - 9783642142437
U6  - http://dx.doi.org/10.1007/978-3-642-14243-7_45
N1  - Notes on numerical fluid mechanics and multidisciplinary design 112
SP  - 365
EP  - 372
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Götten, Falk
A1  - Havermann, Marc
A1  - Braun, Carsten
A1  - Gomez, Francisco
A1  - Bil, Cees
T1  - RANS Simulation Validation of a Small Sensor Turret for UAVs
JF  - Journal of Aerospace Engineering
N2  - 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.
Y1  - 2019
U6  - http://dx.doi.org/10.1061/(ASCE)AS.1943-5525.0001055
SN  - 1943-5525
VL  - 32
IS  - 5
PB  - ASCE
CY  - New York
ER  -