EFFECTIVE THERMAL CONDUCTIVITY FOR GRAN-ULAR BEDS OF VARIOUS BINARY MIXTURES

Abstract

The effective thermal conductivity was investigated for granular beds of various binary mixtures. Samples used were two or three sizes of glass beads, resin particles and copper spheres respectively. A unit cell model was developed after due consideration of particle diameter ratio and it was assumed that the coordination number was a function of diameter ratio and volume fraction of components. Predicted values coincided with experimental ones, in which the ratio of diameters was 1-2.8 and the ratio of solid conductivities was 1-5.8, within 6% deviation.