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A series of experimental and theoretical investigations was conducted to understand moisture and heat transfer in different unsaturated porous media at pore scale level with the consideration of phase change, including water wetting of a dry wood, heat and mass transfer in sand packed beds with locally heating, boiling phenomena in bead-packed porous structures, vapor condensation and vapor/liquid transport in unsaturated materials, and drying of porous media containing concentrated solutions. A number of new phenomena were observed from the experiments, and important transport characteristics of these phenomena were discussed from theoretical investigations. Special attention was paid to the effects of pore structure, phase change interface, salt precipitation from solution, and some theoretical descriptions and explanations were developed to explore fundamentals of the phenomena. [ABSTRACT FROM AUTHOR]

Numerical investigations were conducted to understand forced laminar fluid flow over coiled pipes with circular cross-section. The focus was addressed on exploring the convective heat transfer from conical and helical coils with comparative studies. The same numerical investigation method was applied to the two differentially coiled pipes (helical and conical) and for different Reynolds numbers corresponding to five cases of exterior flow arrangement. The results show better heat transfer performance for cases of conical coils where much flow turbulence was observed due to an effective flow arrangement. [ABSTRACT FROM AUTHOR]

An investigation was conducted to understand thermally fully developed convective transport phenomena induced by both electroosmosis and pressure gradients in a narrow parallel channel. A model was developed to describe the fluid flow and associated heat transport phenomena. Both the dimensionless temperature profile and the Nusselt number were obtained analytically with and without Joule heating with an investigation conducted to understand the importance of Joule heating and the ratio of the hydraulic flow rate to the electroosmotic flow rate. The emphasis of the comprehensive discussion is on understanding the physical significance of the singularities of the flow behavior and heat transfer. [ABSTRACT FROM AUTHOR]