Potential Flow Model for Gaussian Plume Interaction with Simple Terrain Features

摘要

The theory of turbulent plumes embedded within potential flow fields is discussed for flows modified by special complex terrain situations. Both two-dimensional and three-dimensional isolated terrain obstacles are considered. Concentration estimates are evaluated using a Gaussian solution to the appropriate diffusion equation; dispersion coefficients are modified to account for terrain-induced kinematic constraints, and plume centerline trajectory is obtained from a stream line of the potential flow. Specific limitations to the theory and its applicability are reviewed. A computer algorithm is developed and documented to perform these calculations. Dispersion estimates and ground-level concentrations are given for a variety of meteorological situations. Parameters of the problem include obstacle height, effective source height, distance between source and obstacle, crosswind aspect ratio of the obstacle, and atmospheric stability. The potential flow theory, originally applicable to neutral flows, is extended by an empirical approximation to slightly stable flows. Model computations are compared to laboratory experimental results for neutral and stable flows, and to field measurements from the Tennessee Valley Authority Widow Creek Power Plant.