Double diffusive natural convection in a doubly stratified wavy porous enclosure

摘要

Combined heat and mass transfer process by natural convection along a vertical wavy surface in a thermal and mass stratified fluid saturated porous enclosure has been numerically analysed. Finite element method has been used and the influence of varying flow, heat and mass transfer governing parameters has been reported. Presence of thermal and mass stratification terms reduces the Nusselt number and Sherwood number values in all the cases. The flow circulation pattern which is anti-clockwise when the species buoyancy forces are opposing the thermal buoyancy forces, gets clockwise when the forces are aiding. When the two buoyancy forces are equal and opposing, a multi-cellular pattern with alternating circulation orientation manifests. Several other interesting features such as thermal and mass boundary layers, thermal plumes, secondary circulation zones, flow intensification etc. are noticed in the flow, temperature and concentration fields with varying flow, heat and mass transfer governing parameters.