Modelling and numerical solution for primary and secondary pollutant with different sources

Simultaneous unsteady advection – diffusion equations have been solved numerically to predict the concentration of primary and secondary pollutant. Mathematical model has been solved considering elevated time dependent line sources for primary pollutant. Three types of sources have been taken (a) instantaneous (b) step type function and (c) cross wind continuous and it is assumed that some part of primary pollutant is converting into secondary pollutant continuously and there is no direct source of secondary pollutant. A mixed finite difference scheme has been used to solve the model. Numerical results have been presented in graphical form. It has been found that concentration is very high in the case of instantaneous source though its spread is very less in comparison to other two sources for both the pollutants. In step type function concentration diminishes very fast in comparison to continuous source. It has also been observed that effect of power law profile of wind tilts the spread of concentration upwards.