Numerical simulation of wind environment in complex terrain engineering site under severe typhoon in Hainan Island

Under the influence of strong typhoons, the wind speed within the wind field in complex terrain exhibits strong non-uniformity. In the report, the Maiwan Water Conservancy Project site in Tunchang County, Hainan Province, was used as the example, and the Computational Fluid Dynamics (CFD) numerical simulation methods were used to analyze the wind environment of the site. The results indicated that the speed of the incoming wind reduced with varying degrees when passing the dam site. The degree of reduction was related to the direction of the incoming wind. At wind direction angles ( 45° to 90°), with the increasing of the wind direction angle, the blocking effects of the adjacent mountains on the incoming wind gradually increased. At wind direction angle ( 180° ), due to the absence of mountain obstruction, the wind speed at the project site was higher. Under the wind direction angle (0°) and the wind speed ( 60 m/s), the wind speed was higher at the intersection of the dam sides and the mountains. A gradient wind height of 300 m above ground level was considered reasonable for the project site, which was slightly less than the gradient wind height of 350 m specified in China standard of B terrain Category.