The shelter effect of porous wind fences on coal piles in POSCO open storage yard

The shelter effect of porous wind fences on surface pressure and wall shear stress acting on the consecutive coal piles of 1/800 scale POSCO open storage yard model was investigated experimentally. The storage yard model was fully embedded in a neutral atmospheric surface boundary layer over open terrain. Reynolds number based on the coal pile height was Re=18,000. The mean and fluctuating surface-pressure distributions on the coal piles, which were directly related to the dust emission from the surface, were measured for several oncoming wind directions. The daily and monthly wind data over the storage yard during two years were statistically analyzed. As a result, a fence of porosity ε=40% was found to be effective for decreasing the mean pressure and pressure fluctuations on the coal piles. In addition, the wall shear stress on the windward surface decreased more than half of that for the no fence case. In order to get a good shelter effect for a large-scale open storage yard, the porous fence should be installed along all peripheral sides of the storage yard, and an additional middle fence is needed for every five consecutive piles to prevent the decreasing shelter effect from descending shear flow separated from the wind fence.