Numerical Simulation of Wind Loads and Wind Induced Dynamic Response of Heliostats

Abstract

This paper presents a numerical simulation method for wind loads fluctuations on heliostats and analyzes the dynamic response of the heliostat which is compared with the tested data. Based on the tested wind data, the target spectrum of wind velocity was determined for the numerical simulation of wind velocity. The time history of wind velocity fluctuation was simulated using an Auto-Regressive (AR) mathematical model. Under the simulated wind velocity fluctuation, a modal and transient analysis was performed using the computational model of the heliostat in ANSYS to determine the dynamic response of the heliostat structure under the transient loads. In this paper, the directional deformation in the direction of wind load was obtained under the wind pressure fluctuation. Then, the deformation was converted to acceleration by differentiation using MATLAB. The simulated time history of acceleration was analyzed in the frequency domain and compared with the tested acceleration. For the simulated acceleration, the dominant frequency value of 3.16Hz had the highest probability of occurrence. For the tested acceleration, the corresponding frequency was 3.18Hz. These results demonstrate the wind-load simulation method and dynamic response analysis presented in this paper for heliostat performance analysis. In future work, methods for wind-load simulation or calculation should be explored to further improve the simulation accuracy.