ABSTRACT

Basic concepts of convection heat transfer in confined conduits fully or partially filled with porous media are overviewed in this chapter. Particular attention is paid to heat transfer in open-celled foams. Results of a recent experimental campaign on the determination of “effective thermal conductivity” in fluid-saturated open-celled foams are presented. To this end, an additive approach is adopted, in which the effective thermal conductivity is calculated based on a superposition of three effects, namely conduction, radiation, and dispersion. The former two effects can be quantified in a porous medium filled with a stagnant fluid while the latter arises due to the fluid flow. Moreover, recent experimental results on the “fluid-to-solid interfacial heat transfer coefficient” are outlined, based on which the possibility of using an approach similar to the Generalized Lévêque Equation (GLE) for the determination of this quantity is discussed. Such an approach allows calculating the heat transfer coefficient based on less complicated pressure-drop measurements.