Wind characteristics of grid-generated wind field along the wind tunnel

Grid-generated wind fields are commonly applied in various wind tunnel tests to ob-tain aerodynamic parameters of flexible bridges.In this work,wind characteristics of grid-gener-ated wind field were investigated at different distances from the grid section along the wind tun-nel.The wind characteristics principally depend on the distance,the thickness of slat and the length of the unit grid side.The results indicate that the mean wind velocity descends steeply and soon afterwards steadies with the distance.The total turbulent energy declines and the dominant energy migrates to the higher frequency region with the distance:the turbulence intensity de-clines and the integral length scale increases;non-dimensional power-spectral density forms and non-dimensional frequencies corresponding to the peak value remain unchanged,but the peak val-ues decline.Two specific turbulent conditions were adjusted according to these contributing fac-tors:similar turbulence intensities with different integral length scales;similar integral length scales with different turbulence intensities,founding the basis to investigate the effects of main wind characteristics on the aeroelastic parameters.