Simulation of snow distribution on typical roofs using coupled CFD and DEM methods

In order to predict snow distribution on a roof caused by snow drift, a simulation based on coupled CFD(computational fluid dynamics)and DEM(discrete element method)methods was employed. The numerical simulation method includes motion equations of fluid and snow particle, fluid-snow particle coupling control equation and snow particle collision model on the coupling condition. Coupled computing method, material parameters of snow particle, the parameters of the collision and border control conditions was built based on the measured results. A simulation of the snow drift adopting this method on a typical Tsuchiya stepped roof was done. Compared the simulated results of snow distribution on the lower roof with previous data from field measurement and wind tunnel test, the feasibility of using coupled CFD and DEM methods to study snow drift was demonstrated. Numerical simulation shows that backflow whirlpool decreases obviously above the low roof due to the existence of snow, the nondimensional horizontal wind velocity on the end of the lower roof is -0.4 when there is no snow distribution, but it increases to 0 with snow distribution. © 2017, Editorial Office of Journal of Building Structures. All right reserved.