Wind tunnel simulation of time variations of turbulence and effects on pressure on surface-mounted prisms

Roughness elements are usually added in boundary layer wind tunnels to enha nce the energy of certain turbulence scales and their range. In this work, flow characteristics in three different configurations of roughness element s are examined. Orthonormal wavelets are applied to velocity records in ord er to quantify the percentage of energy contribution of each scale to the t otal energy and the intermittency of high-energy events. The effects of suc h variations in turbulence scale characteristics on variations of peak and mean negative pressure coefficients at different locations on a 1:50 scale model of the Wind Engineering Research Field Laboratory (WERFL) of Texas Te ch are also determined. The results show that enhancing the energy of the s maller turbulence scales relative to that of the larger scales and in parti cular the energy of the intermittent events have significant effects on mea n and peak pressures observed on the top surface of a prism. (C) 2000 Elsev ier Science Ltd. All rights reserved.