Impact of thermal and solute source-sink combination on thermosolutal convection in a partially active porous annulus

Abstract

Abstract The objective of the current paper is to investigate the thermosolutal flow along with heat and mass dissipation rates in an upright porous annular space subjected to discrete heating and salting along the vertical boundaries with insulated and impermeable horizontal boundaries. To solve the model equations, an implicit finite difference scheme with over relaxation technique has been implemented. The numerical predictions focus specifically on the effect of buoyancy ratio, Lewis number, Darcy number and source-sink arrangements on fluid flow behavior, thermal and solutal characteristics, average Nusselt and Sherwood numbers. The simulations were performed for an extensive range of dimensionless parameters (−10 ≤ N ≤ 10, 0.1 ≤ Le ≤ 1, 10−5 ≤ Da ≤ 10−1) by considering two different types of source-sink arrangements and found that the flow circulation strength is maximum with in-line arrangement of source and sink compared to alternative arrangement. Also, we found that in case-I, regardless of Lewis number, the maximum heat and mass dissipation rates takes place through top source during opposing flow, and through bottom source for aided flow. However, in case-II arrangement, irrespective to type of flow, the greater amount of heat and mass transport is found through the bottom source at the inner cylinder compared to top source placed at outer cylinder.