University of Cambridge > Talks.cam > Fluid Mechanics (DAMTP) > Particle entrainment into avalanches: Driven by pore pressures?

Particle entrainment into avalanches: Driven by pore pressures?

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There is compelling field, laboratory and DNS evidence of large vortex structures within the heads of snow avalanches. In this work we propose that the pore pressures these structures induce within the snow pack are sufficient to fluidize the pack and feed the avalanche, contrasting with a traditional approach that assumes particle entrainment is a result of bed shear stresses. We model the powder snow avalanche as a potential flow consisting of a dense source of material thrust into a uniform airflow. The resulting flow field yields pressure gradients that lead to further snow entrainment allowing the powder avalanche to sustain itself. Stability analysis of a mass balance involving snow cover and powder cloud yields relations for scouring depth, frontal height, speed, density, and impact pressure when the frontal region achieves a stable growth rate.

This talk is part of the Fluid Mechanics (DAMTP) series.

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