Numerical Simulations Of Blowing Snow With Mixed Diameter

In this paper, we established a numerical model of blowing snow evolution, the number of snow particles in the air of mixed diameter and uniform diameter with time and the snow transport rate with time and height during the development of saltation snow particles, as well as the concentration with height of the suspension snow particles are analyzed in detail. The results showed that:1) For the saltation snow grains, the particles’size distribution on bed and in air were consistent both on the bed and in the air, the horizontal take-off velocity increased with the grains size at first and then decreased with their size, furthermore, the vertical take-off velocity with their size has the same trend.2) The number of the grain exsit in air and snow transport rate rapidly increased with time, and the duration time to reach a steady state decreased with friction speed gradually.3) The grain number in air for mixed diameter snow particles was less than uniform diameter snow particles at the steady state. However, the law for the snow transport rate with time was opposite to the snow grains in the air, also the duration time for the mixed snow grains reached a steady state lagged behind the uniform snow particles’ and the lag time gradually decreased with the friction speed.4) Snow transport rate of mixed diameter with height at steady state was greater than uniform snow particle’s.5) For the suspension snow grains, the concentration at the steady state increased with the friction speed. At the same height, friction speed has great influence on the concentration. Moreover, the concentration of uniform diameter snow grains greater than mixed particle’s for suspension.