Heliostat Wind Loads

Wind load predictions for heliostats are not provided in design codes because of their non-standard shape and the changes in wind velocity and turbulence in the lowest 10 m of the atmospheric boundary layer (ABL). The Heliostat Design Wind Loads Spreadsheet estimates the design wind loads on different heliostat sizes based on:(1) the dependence of wind load coefficients on turbulence intensity derived in our wind tunnel experiments,(2) the expected wind speed and turbulence intensity profiles in the full-scale ABL.Mean and peak design loads are calculated for a square-shaped heliostat based on the mean wind speed and the relevant aerodynamic coefficient. Critical load cases show the maximum value of the heliostat loads and aerodynamic coefficients for each load case.鉴于定日镜外形非标准化，且大气边界层（Atmospheric Boundary Layer，ABL）底部10米范围内的风速与湍流特性存在显著变化，现行设计规范中并未提供定日镜的风荷载预测值。本定日镜设计风荷载电子表格工具，基于以下两项依据估算不同尺寸定日镜所承受的设计风荷载：(1) 本团队风洞试验中推导得到的风荷载系数与湍流强度的相关性；(2) 足尺大气边界层（ABL）中预期的风速廓线与湍流强度廓线。该工具将基于平均风速与对应气动系数，计算方形定日镜的平均设计荷载与峰值设计荷载。关键荷载工况模块可展示各荷载工况下定日镜所受荷载与气动系数的最大值。