Large eddy simulation of flow around a low-rise building immersed in turbulent boundary layer

A turbulent boundary layer developed on the flat plate was simulated using large eddy simulation,and a quasi-periodic boundary condition was used to keep boundary layer thickness constant.Velocity and pressure history were extracted from the turbulent boundary layer and were set as the inflow condition for the flow simulation around a low-rise building,flow and pressure characteristics under turbulent inflow were studied.The results show that the properties of turbulent inflow can be well preserved in non-uniform grid system.Velocity profile,turbulent intensity and spectrum properties of the inflow are similar with those of wind field on open area.Mean and fluctuating pressure coefficients on building surface are basically in agreement with wind tunnel test,except for the flow separation regions,which could be attributed to discrepancy of the turbulent intensity and Reynolds number between present simulation and wind tunnel test.The pressure on the roof shows non-Gaussian property,especially in flow separation region,such as windward edge and side edge.The non-Gaussian properties are in good agreement with wind tunnel test.Due to the pressure non-Gaussian properties,higher peak factors are recommended when predict gust pressure on the roof,the value of g=4.5-5.5 are recommended.