A 2-TEMPERATURE MODEL FOR TURBULENT-FLOW AND HEAT-TRANSFER IN A POROUS LAYER

A new model of turbulent flow and of two-temperature heat transfer in a highly porous medium is evaluated numerically for a layer of regular packed particles. The layer can have heat exchange from the defining surfaces. The commonly used models of variable morphology functions fa r porosity and specific surface were used to obtain comparisons with o ther works in a relatively high Reynolds number range. A few outstandi ng features of the closure models for additional integral terms in equ ations of flow and heat transfer are advanced. Closures were developed for capillary and globular medium morphology models. It is shown that the approach taken to close the integral resistance terms in the mome ntum equation for a regular structure can be obtained in a way that al lows the second order terms for laminar and turbulent regimes to natur ally occur. These terms are taken to be close to the Darcy term or For chheimer terms for different flow velocities. The two-temperature mode l was compared with a one-temperature model using thermal diffusivity coefficients and effective coefficients from various authors. Calculat ed pressure drop along a layer showed very good agreement with experim ent for a porous structure of spherical beads. A simplified model with constant coefficients was compared with analytical solutions.