HEAT-TRANSFER MEASUREMENT AND ANALYSIS FOR SINTERED POROUS CHANNELS

This paper presents the results of heat transfer measurement and analysis for two 5 x 5 x 1 cm porous channels. The channels were made of sintered bronze beads with two different mean diameters, d(p) = 0.72 and 1.59 mm. The local wall temperature distribution, inlet and outlet pressures and temperatures, and heat transfer coefficients were measured for heat flux of 0. 8, 1.6, 2.4, and 3.2 W/cm2 with air velocity ranging from 0. 16 to 5 m/s and inlet air pressure of 1 approximately 3 atm. The measurement covers the data in both thermal entrance and thermally fully developed regions. The local Nusselt numbers were correlated in the fully developed region. The fully developed Nusselt numbers were analyzed theoretically by using a non-Darcy, two-equation flow model. Heat transfer between the solid and fluid phases was modeled by a relation of the form h(loc) = ARe(n). A wall function was introduced to model the transverse thermal dispersion process for the wall effect on the lateral mixing of fluid. The predicted fully developed Nusselt numbers are in good agreement with the measured values.