Thermal Nonequilibrium Between Fluid and Solid Phases

In this chapter we examine the single-phase flow through solid matrices where the assumption of the local thermal equilibrium between the phases is not valid. When there is a significant heat generation occurring in any one of the phases (solid or fluid), i.e., when the primary heat transfer is by heat generation in a phase and the heat transfer through surfaces bounding the porous medium is less significant, then the local (finite and small) volumes of the solid and fluid phases will be far from the local thermal equilibrium. Also, when the temperature at the bounding surface changes significantly with respect to time, then in the presence of an interstitial flow and when solid and fluid phases have significantly different heat capacities and thermal conductivities, the local rate of change of temperature for the two phases will not be equal.