Modelling and numerical simulation of snow drift around snow fences

A method for computer simulations of snow drift around man made structures is described. Particles are tracked in space and time based on a Lagrangian-Eulerian description of particle and wind velocities, respectively. Calculation of the wind phase is governed by the general Navier-Stokes equations and the proposed equation for particle motion covers both suspension and saltation effects. Saltation is modelled on a statistical basis by assuming random particle distribution in the saltation layer similar to real measurements of vertical mass concentration. Particles are programmed to depart from the surface by saltation provided that the wind is above threshold. Some of the snow particles will then return to the surface while others will remain in suspension in the wind. Computer simulations of snow drift around a two dimensional Wyoming snow fence are performed with a fence height of 2.74 m and a porosity of 50%. The results are in good comparison with the measured equilibrium drift profile typical for such a snow fence.