LES Analysis of the Effect of Snowdrift on Wind Pressure on a Low-Rise Building

This paper presents a comparative study of the distribution of wind pressure acting on a low-rise building roof with or without snowdrift through the Large-Eddy simulation (LES) method. Firstly, based on previous wind-blowing snow experiments, the stable snowdrift models were obtained by reverse technique. Secondly, the methodology of LES numerical simulation was introduced, where sensitivity analyses were conducted to determine a more reasonable grid configuration and data sampling time. Meanwhile, the numerical validation was also verified by comparing it with the previous PIV database. Finally, the wind pressure acting on the building's roof with or without snowdrift were systematically compared and analyzed. It was found that the snow cover significantly restrains the size of the separation bubble and makes is lcoated earlier on the roof, which leads to the increasing passing velocity in the region near the roof. Meanwhile, the area-averaged pressure coefficient in the windward region (x/H < 0.5) for the snowdrift roof will be significantly amplified, especially for the fluctuating pressure, the maximum value of the Relative Difference even reaches 40%. Additionally, according to the POD analysis, the snowdrift causes the fluctuating wind energy to concentrate near the windward side of the roof. Therefore, more attention should be paid to the wind pressure in the windward region when the snowdrift is formed on the roof.