Numerical Study of Double Diffusive Convection in a Lid Driven Cavity with Linearly Salted Side Walls

Abstract

Double diffusive convection phenomenon is widely seen in process industries, where the interplay between thermal and solutal (mass) buoyancy forces play a crucial role in governing the outcome. In the current work, double diffusive convection phenomenon in a lid driven cavity model with linearly salted side walls has been studied numerically using Finite element simulations. Top and bottom walls of the cavity are assumed cold and hot respectively while other boundaries are set adiabatic to heat and mass flow. The calculations of energy and momentum transport in the cavity is done using velocity-vorticity form of Navier-Stokes equations consisting of velocity Poisson equations, vorticity transport, energy and concentration equations. Galerkin’s weighted residual method has been implemented to approximate the governing equations. Simulation results are obtained for convective heat transfer for 100<Re<500, 50<N<50 and 0.1<Ri<3.0. The average Nusselt number along the hot wall of the cavity is observed to be higher for higher Richardson number when buoyancy ratio is positive and vice versa. Maximum Nusselt number is recorded at buoyancy ratio 50 and Richardson number 3.0, on the other hand low Nusselt number is witnessed for buoyancy ratio 50.

Keywords

• Double diffusive mixed convection; Mass buoyancy force; Convective heat transfer.