Variable Density Turbulence Tunnel
Present configuration and existing infrastructure:
Passive grids are mounted at the upstream end of the measurement section to generate turbulence. Three grids can be installed with 53.3mm, 106.6mm, or 186.6mm grid spacing. These are biplanar grids of bars with square cross section that block 40% of the cross section. The integral scales of the flow are approximately equal to the grid spacing, and the turbulence intensities are 2-3%.
The grid is visible at the upstream end of the test section, which is octagonal. The wind blows toward the camera. The blue bars are elements of a linear traverse that moves up and down the length of the tunnel.