Numerical Simulation Of Snow Drifting On The Roof Of Pyramidal Hipped House

Pyramidal hipped house is widely used in civil and camping houses.It is more sensitive to the effect of wind and snow when its weight is light.Wind and snow loads are often controlled loads in structural design,especially the non-uniform snow loads under wind force have greater impact.However,the current "Load Code for the Design of Building Structures"(GB 50009-2012)only gives roof snow distribution factor of a limited number of house types according to experience and foreign codes and datas.Domestic and foreign load codes don’t involve pyramidal hipped house,and it can only refer to other similar body types during design,which may cause unreasonable design or potential safety hazards.Therefore,it is of great theoretical significance and engineering application value to study the snow drifting on the roof of pyramidal hipped house.Numerical simulation was conducted to research the snow drifting on the roof of pyramidal hipped house based on Euler-Euler method and the one-way coupling assumption of wind and snow,considering the saltation and suspension of snow particles and using computational fluid dynamics software.The Mixture model was selected to simulate the snow drifting around a cube and on a stepped flat roof.The reliability and reasonability of numerical simulation method was verified by comparing the simulation results with the observed datas,and the key techniques and parameters of numerical wind tunnel were discussed and analyzed.The analysis models were designed according to functional requirements of pyramidal hipped house.The reasonable partition of roof was determined on the basis of trial calculation.Regarding wind speed 5m/s,7m/s,9m/s,11m/s,13m/s,15m/s,wind direction 0°,15°,30°,45°,and roof slope 25°,30°,34°,40°,45° as variable parameters,through numerical simulation of 120 working conditions for pyramidal hipped house,the basic law of erosion and deposition on roof is obtained,and the roof snow distribution factor which can be used for snow resistance design is put forward.The results show that the change of wind direction angle will lead to a great change in the snow distribution on the roof,and the mutual transformation of erosion state and deposition state will occur in some areas.Changes in wind speed and roof slope have a greatimpact on the overall snow cover.When the wind speed exceeds 9 m/s,the windward side is completely eroded.When the slope is large,the whole roof is in an erosive state,and when the slope is small,the windward side only erodes,and the leeward side is deposited under some working conditions.