Resumen de Simulación física y numérica de las avalanchas de nieve en Francia
In this paper are presented and described the main characteristics of the different kind of snow avalanches. We distinguishes two great families : dense and powder avalanches. Their releasing conditions are reminded and their dynamics and effects are described. A modelling based on Saint Venant equations (completed by a Bingham reological model) is proposed far the dense avalanches. Concerning powder avalanches their similarity with gravity currents al/ows to undertake a physical modelling. This physical modelling is succinctly described and the densimetric Fraude similarity criterium is presented. The numerical modelling of this kind of ava/anches (based on Navier-Stokes equations and on a turbulence model) is showh. The comparison between the two models is made in the case of a turbidity current. The numerical modelling allows to find global characteristics of the flow (such height and velocity of the avalanche front) and allows especially to access to the internal variables (pressure, concentration, velocity and turbulence characteristics).
