Entropy Generation Due to Double-Diffusive Natural Convection in Partly Porous Cavity Under Local Thermal Non-equilibrium State and Non-uniform Heating and Salting

In this work, we conducted a numerical analysis to examine entropy generation within a cavity consisting of two distinct layers: a porous layer and a clear binary fluid layer, adopting the local thermal non-equilibrium model between the solid of the porous layer and the saturating binary fluid. The governing dimensionless coupled partial differential equations, which include the two energy equations for fluid and solid phases, the momentum equations, and the entropy generations equations, are discretized using the finite volume method. The effects of several key parameters on internal irreversibility due to heat transfer in the solid and fluid phases are investigated. These parameters include the buoyancy ratio ( \(N\) ), dimensionless porous layer thickness ( \(\Delta\) ), dimensionless inter-phase heat transfer coefficient ( \(H\) ), modified thermal conductivity ratio ( \(\gamma\) ), and the porosity of the porous layer ( \(\varepsilon\) ). It is found that, in addition to the effect of the physical properties, \(H\) and \(\gamma\) , on the thermal equilibrium between the porous layer and the saturating binary fluid, the geometrical properties, \(\Delta\) and \(\varepsilon\) , play a dominant role in the choice of the appropriate physical model (LTE or LTNE) when studying heat transfer in a porous medium.