摘要

The ability to predict in advance the dispersion patterns of contaminants released into our local working environment, atmosphere, or oceans can aid in minimizing contamination of the local and global environment. A practical method used to achieve this aim is the Fokker-Planck solution—the concentration equation used to determine the dispersion pattern of a contaminant—and much research into this solution, both theoretical and numerical, has been undertaken. Obtaining physical realistic results requires an accurate numerical solution of the concentration equation in conjunction with the Navier-Stokes equations and a suitable turbulence model. This article considers the equations governing the release of a buoyant contaminant and presents a practical method for decoupling the Navier-Stokes and concentration equations. This permits the concentration equation to be solved even when the flow field is already known—for instance, from experiment. Furthermore, a simple yet effective numerical procedure is developed that increases the accuracy of the numerical solution of the governing equations of motion. These methods will be applied to model the release of a contaminant in the neighborhood of large-scale topography within the atmosphere; however, the techniques could be applied to a wide variety of engineering problems.