Control of Turbulence in a Multiple-Fan Wind Tunnel

Abstract

Multiple-fan wind tunnels have been developed in our laboratory to estimate the wind effects on large structures, such as high-rise buildings, long-span bridges, etc.. It is well known that natural turbulent wind can be analyzed by statistical factors, such as mean wind velocity,turbulent intensity, turbulent scale, power spectrum, Reynolds stress and so on. In the previous papers, it was shown that these factors were able to be simulated simultaneously in the multiple-fan wind tunnels. Moreover, to investigate the dynamic response of a large structure in a turbulent strong wind, spatial structure of the strong wind should be reproduced in the wind tunnels together with above factors. The spatial structure is expressed by coherence and phase-lag. It is shown in this paper that the coherence was obtained closely to the target by giving the phase-lag as a random function related to the coherence target.