Effect of density maximum of water on natural convection in a porous cavity

The effect of density maximum on heat transfer due to the buoyancy-driven flow of water inside a water-saturated porous medium with differentially heated sidewalls is studied numerically. The finite volume method is used to discretize the governing equations, which are solved by Gauss-Seidel and successive overrelaxation methods. The phenomena are discussed for different values of porosity, Darcy number, and Grashof number. The temperature distribution and flow fields are depicted in the form of streamlines, isotherms, and midheight velocity profiles in the figures. It is found that the effect of maximum density is to slow down the natural convection and reduce the average heat transfer. The strengths of convection and heat transfer rate become weak due to more flow restriction in the porous medium for a small porosity.