Item: A three dimensional dynamic model of turbulent avalanche flow
Title: A three dimensional dynamic model of turbulent avalanche flow
Proceedings: 1986 International Snow Science Workshop, Lake Tahoe, California, USA
Authors: T. W. Tesche
Abstract: Methods for modeling avalanche dynamics have evolved from the analogy with water flow in open channels. Voellmy (1955) pioneered the first general model for avalanche speed and runout distance. Subsequent researchers have extended the one dimensional, steady state theoly to transient flow and quasi-steady two dimensions. Recently, numerical methods have been developed to simulate timedependent two-dimensional, laminar dense flow and turbulent powder avalanches. This paper presents a numerical model of three dimensional turbulent avalanche dynamics. The avalanche is treated as a Newtonian, inhomogeneous, multiphase gravity current in which density stratification is determined by the suspended snow particle distribution. Primitive equations for mass snow volume fraction, and momentum are written with density variation terms retained (i.e., no Boussinesq approximation). A two-equation, second order closure k-e turbulence model for density affected flows is used to complete the Reynolds averaged bulk flow equations. Results of the model initialization scheme for a typical powder avalanche are presented and numerical methods for solving the field equations are outlined.
Keywords: water flow, runout distance, newtonian
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