Author(s): Peter Sampl; Thomas Zwinger

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Keywords: Snow avalanches; Computational fluid dynamics

Abstract: A dry snow avalanche consists of two distinctive layers. A dense flow layer (DFL) with bulk densities up to 400 kg/m3is often superposed by a cloud of relatively small ice particles suspended in air. The density of this suspension, the so called powder snow layer (PSL), is one order of magnitude smaller than that of the DFL. Because of the completely different physical characteristics separate models for both layers are developed. These models have to be coupled by an additional transition-model that describes the exchange of mass and momentum between the layers. The fundamentals of a two-dimensional granular flow model for the DFL and a threedimensional turbulent mixture model for the PSL together with a simple transition model are presented. First results of the complete coupled model applied to an observed catastrophic avalanche event are briefly discussed.

DOI:

Year: 1999