风洞试验中上游地表粗糙度设置对风场与荷载预测精度的影响OA

This paper investigates the application of exposure roughness in the field of wind engineering.A comparative analysis of wind load provisions from different countries reveals how variations in roughness pa-rameters affect design wind pressures.Wind tunnel experiments with two distinct upstream exposure rough-ness conditions are conducted to further investigate the influence of exposure type on the urban atmospheric boundary layer and pedestrian-level wind environment,and to quantify its effect on the accuracy of urban wind field simulations.The results show that appropriate selection of the upstream exposure type immediately is critical for accurate urban wind profile simulation.The parameter regulations for different exposure types in Chinese code yields higher wind speed predictions at elevated heights than other codes,potentially overestimat-ing design wind pressures.Compared with the mean wind speed profile,the upstream exposure type exerts a stronger influence on the turbulence intensity profile,where insufficient upstream fetch length may introduce substantial errors.Additionally,exposure type significantly affects pedestrian-level wind environment simula-tions.When the prevailing wind aligns with the main street orientation,an upstream exposure with excessively low roughness can accelerate street canyon wind speeds,leading to errors exceeding 30%.