ERDC/CRREL TR-12-7 "Effects of Support Structure Porosity on the Drift Accumulation Surrounding an Elevated Building"

This study focuses on the effects of elevated building substructure porosity on the accumulation of drifting snow. We conducted wind tunnel experiments of the snowdrift accumulation and numerical simulations to determine the flow field around a prototypical elevated building (based on the Martin A. Pomerantz Observatory or MAPO) with varying substructure porosity. We found that the total drift volume accumulated decreases as the substructure porosity increases (i.e., the substructure has less clutter). Furthermore, substructure porosity influenced the proportion of the drift deposited upwind or downwind of the structure, with a more porous substructure depositing most of the drift upwind of the structure; for low substructure porosity, most of the drift is deposited in the lee of the structure. Numerical simulations revealed that, for low substructure porosity a separation bubble can form upwind of the building that appears to direct particles over the upwind region of subcritical shear stress and suppress formation of the upwind snowdrift. Porosity and the presence of ground-based clutter also affected the rate of drift encroachment. The results of this study suggest that applying care in the design of the substructure could prolong the life of a building by 2 or more years. DISCLAIMER: The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. All product names and trademarks cited are the property of their respective owners. The findings of this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents. DESTROY THIS REPORT WHEN NO LONGER NEEDED. DO NOT RETURN IT TO THE ORIGINATOR. ERDC/CRREL TR-12-7 iii