2002 Volume 37 Issue 2 Pages 141-154
Wind tunnel tests for atmospheric environmental assessment were performed under neutral conditions. It is important to consider variations in atmospheric stability, especially low-height gaseous sources and complex terrain, in order to estimate exhaust gas diffusion correctly. Simulations of atmospheric diffusion processes under various atmospheric stability conditions were carried out in a thermally stratified wind tunnel. We used the Pasquill-Meade Chart as a template of typical plume spread. Simulated plume spreads agreed with characteristic lines of each atmospheric stability condition that was categorized by Pasquill-Meade in the chart. Turbulence intensities were widely distributed in accordance with stability conditions, similar to real atmospheric phenomenon. Experimental turbulence scales of main flow for all stability conditions behaved like field data, and those of vertical velocity varied, similar to turbulence intensities. Variations of velocity u and w implied an the existence of certain functions, each scaled by suitable parameters. We concluded that fundamental plume spread patterns of Pasquill-Meade Stability Classes enable simulation in the thermally stratified wind tunnel. Through our study, we have determined that it is possible to develop wind tunnel experiments for non-neutral environmental assessment.
