Mean and fluctuating wind loads on rough and smooth domes

Simultaneous pressure measurements have been obtained on rough and smooth parabolic domes in simulated atmospheric boundary layer flow. Mean and fluctuating pressure distributions compare favorably with earlier studies for similar shape and Reynolds number. The effect of surface roughness is to reduce suctions over the apex of the dome and increase suctions in the wake region on the leeward face. The consequence for mean and fluctuating overall loads is reduced uplift but increased drag for rougher surfaces. Correlation analysis of the fluctuating pressures reveals that the first two eigenvectors account for approximately 60% of the fluctuating pressure energy and follow the mean pressure coefficient and its gradient with respect to horizontal wind direction as predicted by the quasi-steady theory. Overall base shear and uplift forces on the domes can be well approximated by this theory. (C) 2000 Elsevier Science Ltd. All rights reserved.