Numerical Simulations Of Blowing Snowdrift On Micro-topography

This paper calculated the flow field with the LES(Large Eddy Simulation) and SIMPLE method(Semi-Implicit Method for Pressure Linked Equations), established a numerical model of blowing snow evolution:1) two phase flow of blowing snow in the case of Flat Ground;2) blowing, snow model in the case of Micro-topography ground and stable input. It simulated the transportation of the snow particles under the different friction, wind speed, surface configuration conditions. It count the flow field, the number of the snow particles, time history of the snow transportation, the distribution situation of the snow transportation along the height, the splashing and settling amount. It analyzed the developing process of blowing snow in the flat ground, the influence of the Micro-topography ground on the stable blowing snow, the characteristic of the stable flow field. It can be concluded that:1)when the snow particles begin to transport rate, the amount of the snow particles in the air, the transportation of the snow increase rapidly with time. With the increment of the friction wind velocity, the time which it need to get stable relatively will decrease.2) When blowing snow is input into the area of micro-topography, the amount of the snow particle in the air and the average value of snow transport rate per unit is greater than that in the flat bed. Both of them has greater fluctuation amplitude than that in flat bed.3)The transportation of the snow decrease with the increment of height. The rate of change decrease gradually. The curve is smooth in flat ground.4) The eroding field and the lodgment field of the snow particle in flat ground will appear alternately. The amount and the range is similar. In Micro-topography ground, it will create an eroding field behind the windward side and a lodgment field in leeside.5) Micro-topography ground can enlarge the blowing snow evolution.