Numerical simulation on the movement characteristics of saltating snow particles

Abstract:

According to the movement mechanism of snow particles, the numerical simulation for a single saltating particle’s trajectory is carried out by using the Lagrange method. At the same time, some of parameters that affect the movement, such as particle diameter, the friction velocity and particle density are analyzed, based on the characteristics of forces applying to the particle. The results show that as the snow particle diameter or particle density increases, the ratio of particle vertical force to gravity decreases and the particle’s saltation height increases. The ratio of horizontal force to gravity varies with the particle’s liftoff velocity, thereby affecting its horizontal saltation length. Based on empirical formula, the relationship between the mass flux of snow surface erosion and the number of saltation particles is established to calculate the mass transport rate of snow particle. And the comparison is made with the calculated results from the classically empirical formula. It is shown that, with the growth of snow particle diameter and friction velocity, particle mass transport rate increases; particle mass transport rate decreases with the increase of the threshold friction speed. The present results in this paper coincide well with Iversen’s empirical formula.