Evaluation of possible effects of admixture sources and diffusion nonlinearity on changes in pollutant concentrations

Abstract

The diffusion equation in aflowing medium of an incompressible liquid describes pollution dynamics. Becouse of complexity of this equation and variety of boundary conditions, the equations of pollutant transfer is solved by numerical methods. In the case of an unlimited and semi-limited medium the equation of pollutant transfer is solved not only by numerical but also by analytical methods. These methods are also applicable for assessing the impact of the field of external pollutants and changes in the boundary conditions. When pollutants spread in a moving medium, nonlinear phenomena, such as eddy fluxes, weak turbulence, etc. can occur. In such cases the nonlinearity of the system should be accounted for. The impact of a weak nonlinearity at a low Reynolds' number is also evaluated in the work.