Reynolds Number Effects on Wind-Induced Responses of a 243-m-High Solar Tower in Elastic Wind Tunnel Tests

Abstract

The effects of Reynolds number on the wind-induced responses of a 243-m-high solar tower are modified by increasing the surface roughness of the test model. First, a series of wind tunnel tests on eight types of circular cylinder test models with different surface roughness are carried out to measure the aerodynamic forces. The results show that the most suitable surface roughness for Reynolds number modification in view of the aerodynamic forces is the height (or the width) of the rib d/D=0.01 and the net distance between adjacent ribs e/D=0.02. Second, the pressure coefficient around the circumference of the rough test model with d=1 mm and e=2 mm are measured to validate the results obtained from force measurement wind tunnel tests. Finally, the wind-induced responses of the 243-m-high solar tower with the selected surface roughness are measured on the basis of elastic wind tunnel tests under a structural damping ratio of 0.3%, 0.7%, 1.0%, 1.5%, and 2.0%. The results show that the RMS wind-induced responses of the solar tower are markedly reduced by taking the effects of Reynolds number into account. However, it seems that the mean wind-induced responses in the along-wind direction have nothing to do with the surface roughness. The wind-induced responses of the rough solar tower decrease with increase of the structural damping ratio. It appears that it is not suitable to totally adopt the current code to determine the wind loads on the solar tower.