SIMULATION~F AIR POLLUTION USINGCOMPUTATI COMPUTATIONAL FLUID DYNAMICS

Abstract

Gases emitted from the chimney are termed as plume. For calculating pollutant concentration we require plume height. Plume is a mixture of gases, considering the plume as ideal gas basic equation like as continuity, momentum and energy equation has been derived. Analytical solutions of these equations are impossible, due to the complexity in mathematical equations. Numerical methods are used for solving these equations. Plume rise equations (continuity momentum and energy) are converted into the dimensionless equation by using appropriate dimensionless 'parameters. In this dissertation finite difference formulation is presented for plume rise equation. The effects of various metrological parameters like• as wind velocity, stability, atmospheric temperature is considered, the other main parameters (plume temperature, buoyancy and initial updraft velocity), which affect the plume height, are also considered. These results are compared with the Briggs 2/3 law. Numerical results of plume under predict the plume height for higher buoyancy factor. Plume rise obtain are low in unstable condition. The pollutant concentration is governed by advection diffusion equation. Numerical solution of the advection-diffusion equation is presented for a ground level source with no effective plume rise. The time-spilt finite volume method (TSFVM) has been formulated. These results are compared with Pasquill-Gifford model for a ground level source with no effective plume rise. Numerical result for a single point source shows that the diffusion coefficients and grid size has effect on the solution accuracy