Numerical analysis of natural convection in a porous cavity with the sinusoidal thermal boundary condition using a thermal nonequilibrium model

Abstract

ABSTRACTSteady non-Darcy natural convection in a porous cavity with sinusoidal thermal boundary condition is studied numerically by adopting the local thermal non-equilibrium (LTNE) model in this paper. The top and bottom walls of the enclosure are adiabatic, whereas the left vertical wall is partially heated and cooled by a sinusoidal temperature profile and the right vertical wall is cooled by the uniform thermal boundary condition. The results show that, compared with the uniform boundary conditions, the sinusoidal boundary conditions can enhance the heat transfer rate of a porous cavity. The values of local Nusselt numbers at the left sidewall can be enhanced by sinusoidal thermal boundary condition and the maximum absolute value of the local Nusselt number appears near the top and bottom walls of the cavity. The thermal nonequilibrium effect on natural convection in the porous cavity can be enhanced by the sinusoidal thermal boundary condition, and the absolute value of the dimensionless solid-to-fluid temperature differences decreases as the thermal conductivity ratio (γ) increases and approaches zero when γ = 10. The periodicity parameter (N) has a significant effect on the heat transfer rate of the porous cavity and the effect of periodicity parameter on heat transfer in porous cavity reduces gradually with the increase of H.