Numerical Analysis Of Combined Heat And Mass Transfer By Natural Convection On Inclined Plates

Combined heat and mass transfer by natural convection which is caused by heat and mass diffusion can be seen in nature and some processes of industry, such as evaporation and desiccation. These processes relate to aeronautics, hydraulics, mechanics, chemical engineering, oceanography and aerography. The characteristic of combined heat and mass transfer by natural convection has been the focus of researches for a long time.Numerical analysis is conducted for combined heat transfer and mass transfer by natural convection on inclined surface. Effects of the inclination angle and the ratio of buoyancies due to heat diffusion and mass diffusion on fluid flow and heat and mass transfer characteristics have been investigated for Pr=0.7 and Sc=0.05-5.0. Numerical results are obtained for velocity, temperature and concentration profiles, variations of both Nusselt and Sherwood numbers under different buoyancy ratio and inclination angles of = 15 -90 .At a given inclination angle, heat and mass transfer rates decrease with heat and mass buoyancies and the buoyancy ratio B decrease from high positive values, and then increase again with the buoyancy radio B further decreasing after the velocity and transfer rates reaching a minimum. The Nusselt and Sherwood numbers increasewith the increasing buoyancy ratio of B . When B reaches Bmin, Nusselt and Sherwood numbers are attained minimum. The value of buoyancy ratio Bmin which is a function of Pr/Sc increase with the increasing Pr/Sc and Bmin varies drastically when 060?.