Numerical Study of the Mass Transfer Effects on the Flow and Thermal Fields Structures under the Influence of Natural Convection

In this paper, a numerical study has been carried out for coupled mass, momentum and heat transfer in the field under effects of natural convection. For this purpose, the unsteady incompressible Navier-Stokes equations with the terms of the Buoyancy forces (due to temperature gradients), energy conservation and concentration (mass) transfer equations have been simultaneously solved using appropriate numerical methods. In order to discretize spatial terms, a combined formulation contains a second-order central difference method and the first-order upwind scheme has been used. Time integration of the governing equation has been performed using the fourth order Runge-Kutta method. The effect of variations of the mass of contaminant has been studied in changing the flow and thermal fields structure. It is concluded from obtained results, an increase in mass flow rate of secondary (mass) injection, alters the structure of the flow and thermal fields. Comparison of the results obtained from the numerical model with appropriate reference data shown that the model has relatively good accuracy.