Experimental study of the torsional aeroelastic instability of single-axis solar trackers under different turbulence intensities

Abstract

To solve the problem of aerodynamic instability of single-axis solar trackers, the present study performs aeroelastic wind tunnel tests of a sectional model under two different turbulence intensities. Large torsional vibrations are reproduced in the wind tunnel, and the wind pressure on the tested model is recorded synchronously to illustrate the interactions between the model motion and the corresponding aerodynamic forces. The basic characteristics of the aerodynamic instability of single-axis solar trackers are clarified by analyzing critical the wind speed and aerodynamic coupling effects. The results show that the wind-induced torsional vibration characteristics are different for different tilt angles and that the range of tilt angles for large torsional vibration under high turbulence is larger than that under low turbulence. At certain tilt angles, external excitation causes large wind-induced torsional vibrations, possibly leading to the different tilt ranges of torsional vibrations under different turbulence intensities. The large torsional vibrations at different tilt angles show two coupling characteristics: strong coupling and weak coupling. The flow state of the windward side contributes significantly to the strong coupling.