The present paper analyses the freezing heat transfer on a cold cylinder immersed in a superheated liquid-saturated porous medium. The main emphasis of this paper is to clarify the effect of natural convection in the liquid phase on the freezing process. A mathematical model was developed, based on several reasonable assumptions for fluid flow in a liquid phase. The governing equations were numerically solved. Numerical results were reported for the thickness distribution of the frozen layer and the heat transfer coefficients at the cold wall and interface. The influences of various parameters such as Rayleigh number, liquid superheat, Stefan number and the dimensionless radius of a cylinder were demonstrated.

This paper investigates mixed free and forced convection of non-Newtonian fluids from a vertical isothermal plate embedded in a homogenous porous medium. A mathematical model is developed based on the modified Darcy's law and boundary-layer approximations, and the exact similarity solution is obtained as well as an integral solution. These two solutions agree within 3% for aiding flows and 10% for opposing flows. It is found that, non-Newtonian characteristics of fluids have appreciable influences on velocity profiles, temperature distributions and flow regimes.

This paper is concerned with forced convection condensation from a vapour-gas mixture on a horizontal plate embedded in a porous medium. It is found that about 50% reduction in heat transfer may be induced by the presence of only 5% non-condensable gas. Furthermore, the reduction is accentuated at lower operating pressures. By comparison it is indicated that forced convection condensation in porous media is much more sensitive to non-condensable gas than that in an open space.

Boundary-layer flow and heat transfer of non-Newtonian fluids in porous media are explored analytically. The local Nusselt number for forced and natural convection of non-Newtonian fluids in porous media on an isothermal semi-infinite plate is obtained as a function of the rheological parameters n and Ω. The results show that these parameters have a significant effect on the heat transfer rate and flow behavior.