Wind loads on heliostat tracker: A LES study on the role of geometrical details and the characteristics of near-ground turbulence

The accurate evaluation of the operational and survival wind loads for ground-mounted heliostat trackers is vital for reducing the total cost during the life cycle of concentrated solar power plants. Current studies rely on reduced scale Wind Tunnel Tests (WTTs), which makes the investigation of the effects of supporting components and near-ground turbulence not trivial. As a result, there is an urgent need to develop complementary techniques to guide wind-resistant designs of commercial heliostats. In this paper, we investigate the performance of Large Eddy Simulations (LES) to systematically study the mean and peak wind loads over heliostats. The effects of elevation and azimuth angles, supports components, turbulence intensity and length scale are investigated. Results show that the proposed LES model accurately reproduces integral force coefficients and the local pressure distributions. Further, an accurate evaluation of the survival wind loads needs to consider the effects of supports components, as they contribute more than 50% to the mean lift and overturning moment in the stow positions. Finally, the effects of turbulence intensity and integral scale are clarified by considering eight different combinations of parameters to characterize the near-ground turbulence. This study provides useful guidelines for design wind loads and lays a solid foundation for LES of heliostat arrays.