Experimental and numerical study is performed to investigate the characteristics of outward freezing heat transfer in water-saturated porous media. Experiments are carried out on a vertical annular space cooled from the inner surface and kept insulated from the outer, lower and upper surfaces. Sandstone grains, glass beads and PVC beads of 16 mm diameter are used as porous media to investigate the thermal conductivity effect on the freezing process. Three different sizes of sandstone grains of average diameters of 4, 8 and 16 mm respectively are used to investigate the effect of the porous matrix.
A mathematical model based on two-dimensional analysis which considered the heat conduction as the only mode of heat transfer in both solid and liquid regions of the PCM. The finite element method is used to develop this model based on Galerkin approach to solve the transient behavior of the freezing in water-saturated porous media phenomenon. Body-fitted curvilinear coordinates are used for treating the freezing front. The effect of thermal conductivity, porosity of the porous media, the wall temperature represented by Stefan number and the initial temperature of liquid phase represented by superheating parameter on the heat transfer characteristics and freezing rate are investigated. Results from the present model have been verified through the comparison with those available in the existing literature and good agreement was observed.