Regensburg 2010 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 9: Granular Matter/ Contact Dynamics I
DY 9.3: Vortrag
Dienstag, 23. März 2010, 10:30–10:45, H47
Velocity Stratification through the Depth in Rapid Shear Flows of Granular Materials — •Birte Domnik1, Christian Kröner1, and Shiva P. Pudasaini1,2 — 1Steinmann Institut, Universität Bonn — 2School of Science, Kathmandu University, Nepal
Appropriate rheology and boundary conditions are required in order to properly determine the dynamics of flow and the impact pressure induced by geophysical and industrial mass flows such as avalanches, debris flows and flow of granular materials. For simulations of ideal fluid, e.g., water, the no-slip is a generally accepted boundary condition which leads to reasonable results. However, it is observed in experiments and in the field that in rapid flow of granular material down the slopes, even the lowest particle layer in contact with the bottom boundary moves with a non-zero and non-trivial velocity. As the material friction substantially influences the flow velocities and also the depth profile an appropriate modelling of the boundary condition is important. In this talk, we present a new continuum mechanical model for rapid motion of granular material down slopes. Possible boundary conditions at the bottom like no-slip, free-slip and, in particular, enhanced approaches will be discussed. In the enhanced approach the bottom velocity can also depend on the bottom pressure. The simulation results demonstrate the applicability of the new model equations, particularly, in the regions where the strong shearing through the depth develops during the motion of the granular mass down the slope.