Variation of the height of centreline of a heliostat and influence on the wind loading

Abstract

Paper presented to the 3rd Southern African Solar Energy Conference, South Africa, 11-13 May, 2015.Mostly located in desert areas, heliostat fields are subjected to various wind conditions. An ANSYS Fluent CFD model of a single heliostat in some worst-case positions is produced using numerical simulations with the realizable k-ε model. The intent of this paper is to show the possible effect that the clearance gap has on the force and moment coefficients of the heliostat. The incoming flow modeled is an ABL profile that has already been generated in a wind tunnel. For a wind angle of 0° and heliostat elevation angles of 90° and 30°, the HCL is varied and the force and moment coefficients are computed. It is shown that the coefficients are sensitive to the clearance gap. More specifically, there is a compromise between lift and drag, and a specific HCL is beneficial to minimize the hinge moment.