Natural convection flows due to the combined buoyancy of heat and mass diffusion in a thermally stratified medium

Laminar, double diffusive free convection is studied numerically adjacent to a vertical surface in a stable, thermally stratified medium. The buoyant mechanisms are thermal diffusion and species diffusion. The species concn. is assumed to be small. Boussinesq approxns. are incorporated and the governing conservation equations of mass, momentum, energy, and species are nondimensionalized. These equations are solved by using a finite-difference method. The results are explained in terms of the basic phys. mechanisms that govern these flows. The ambient thermal stratification has a profound effect on the transport characteristics. The results show many interesting aspects of the complex interaction of the buoyant mechanisms