Unsteady Natural Convection in a Porous Square Cavity Saturated by Nanofluid Using Buongiorno Model: Variable Permeability Effect on Homogeneous Porous Medium

This paper investigated numerically a natural convection in porous cavity saturated by nanofluide. The left and right wall of the are maintained at hot-cold temperature respectively, other walls adiabatic. two-phase Buongiorno model has been adopted to take account Brownian thermophoretic diffusion order demonstrate spatial distribution local nanoparticles concentration. After following temporal evolution different structures (0<τ<5), Numerical simulations performed explore effect density buoyancy (104<Ra<106), permeability homogeneous medium (10-5<Da<10-2), on hydrodynamic, thermal mass behavior. An original motivation was also introduced our work examine linearly variable along opposite direction varying initial Darcy number from (10-5<Da<10-2) fixing final Daf =10-5. dimensionless partial differential equations solved using finite element method. effects governing parameters heat transfer analyzed. Results indicate that stationary regime is formed after unsteady time τ = 0.3. movement nanofluide strongly influenced forces depends number, accentuated for homogenous compared this one with permeability. It found convective flow considerably affected variation consequently reduced.