Transient natural convection heat transfer in nanoliquid-saturated porous oblique cavity using thermal non-equilibrium model

The problem of transient natural convection heat transfer in a nanoliquid-saturated porous oblique cavity is studied numerically using the finite difference method. The hot left wall of the cavity is maintained at a constant temperature and so is the cold right wall. The horizontal walls allow no heat transfer to the surrounding. The Darcy law is used along with the Boussinesq approximation for the flow. The heat transfer equations are those of a two-phase medium, one for the nanoliquid and another for the porous medium. Water-based nanoliquids with Ag or Cu or Al2O3 or TiO2 nanoparticles are chosen for investigation. The governing parameters of this study are the Rayleigh number (10(2) <= Ra <= 10(4)), modified conductivity ratio (0.1 <= gamma <= 1000), inter-phase heat transfer (0.1 <= H <= 1000), inclination angle of the sloping walls (- pi/3 <= omega <= pi/3), volume fraction of nanoparticles (0 <= phi <= 0.2) and dimensionless time (0 <= tau <= 0.1). The assumption of local therma