Modeling of Plume Downwash and Enhanced Diffusion near Buildings: Comparison to Wind Tunnel Observations for in Arctic Industrial Site

Abstract

The ability of a modified Industrial Source Complex model to simulate concentration distributions resulting from high wind speeds (neutral conditions) has been evaluated by comparison to data from a wind tunnel study of a Prudhoe Bay, AK oil-gathering center characterized by short stacks and interconnecting buildings. The model tends to predict correctly the concentrations further downwind (500?1700 m) and underpredict the higher concentrations in the building wake region from 3 to 10 building heights downwind (100?350 m). The model cannot be used to predict concentrations at downwind distances less than 100 m where the maximum concentrations typically occurred. A large variation in the amount of building enhanced diffusion was observed for different wind direction. The Huber-Snyder algorithm could simulate lateral diffusion best when the combined width of all buildings of a height similar to the release height, up to a maximum of 5HB (building height), was considered the dominant length scale. Enhanced lateral dispersion was observed even when the plume reached a height above 1.2HB, estimated with Briggs plume rise equations, at a downwind distance of 2HB.