Transient Evaluation of Wind-Induced Vibration Response of Heliostat Under Downburst

As the region with the highest amount of solar radiation, Qinghai-Tibet Plateau has the highest frequency of thunderstorms in China. Downburst generated in thunderstorm can cause high-intensive wind near the ground, which is a critical threat to heliostats. Herein, the impact of the wind loads on the heliostat response under downburst is investigated using a proven finite-element model and the influence is also compared with that under atmospheric boundary layer (ABL) wind. The results demonstrate that the downburst development process, the movement of the storm center, and the heliostat's elevation angle are highly associated with the wind-induced response characteristics of the heliostat under downburst. The maximum displacement and stress of the heliostat with different elevation angles under the downburst are significantly larger than those under ABL wind. Additionally, when the elevation angle of the heliostat is 30 degrees, the maximum value of the mirror's first principal stress under downburst is 1.88 times greater than it is under ABL wind. Therefore, the impact of wind-induced vibration caused by downburst is necessarily considered on the safety of heliostat in Qinghai-Tibet Plateau with abundant solar energy resources and high incidence of downbursts.