Double-diffusive and Soret-induced convection of a micropolar fluid in a vertical channel

This paper reports an investigation of the fully developed natural convection heat and mass transfer of a micropolar fluid in a vertical channel. Asymmetric temperature and concentration boundary conditions are applied to the walls of the channel. The cases of double diffusion and Soret-induced convection are both considered. The governing parameters for the problem are the buoyancy ratio and the various material parameters of the micropolar fluid. The resulting non-dimensional boundary value problem is solved analytically in closed form using MAPLE software. A numerical solution of the time dependent governing equations is demonstrated to be in good agreement with the analytical model. The influence of the governing parameters on the fluid flow as well as heat and solute transfers is demonstrated to be significant.

► We examine natural convection of a micropolar fluid in a vertical channel. ► The cases of double diffusion and Soret-induced convection are both investigated. ► The flow direction depends on the sign of the buoyancy ratio of the mixture. ► Upon increasing the vortex viscosity the fluid velocity is inhibited. ► The heat added to the fluid is higher for double diffusion than Soret convection.