Numerical Simulation of Double Diffusive Laminar Mixed Convection in a Horizontal Rotating Annulus Part (I): Effect of Richardson and Lewis numbers

Abstract

A numerical study of double-diffusive mixed convection within a horizontal rotating annulus has been investigated. The outer cylinder is fixed but the inner cylinder is considered to rotate in clockwise and anti-clockwise directions to introduce the forced convection effect. In addition, the solutal and thermal buoyancy forces are sustained by maintaining the inner and outer cylinder at uniform temperatures and concentrations but their values for the inner are higher than the outer. The flow is considered laminar regime under steady state conditions. The transport equations for the continuity, momentum, energy and mass transfer are solved using the finite volume technique. The considered domains in this investigation are: 0.01? Ri ? 100 and 0.01 ? Le ? 100. While the thermal Grashof number, Prandtl number, buoyancy ratio and the radius ratio are kept constant at values equal to104, 0.7, 1 and 2 respectively. The effect of the selected parameters on the local and average Nusselt and Sherwood numbers are presented and studied. Finally, this investigation concerned with selection the best direction of the inner cylinder rotation to enhance both heat and mass transfer. A comparison was made with the published results and a good agreement was found.