EFFECTIVE THERMAL-CONDUCTIVITY OF COMPOSITE-MATERIAL WITH SPHERICAL INCLUSIONS IN ORTHORHOMBIC STRUCTURE

The present study is to investigate the effective thermal conductivity of a composite where spherical inclusions of constant size and therma l conductivity can be ideally dispersed as an orthorhombic structure. The three-dimensional heat conduction problem with complex geometry ha s been calculated by the finite element method accompanied by automati c mesh generation to simplify the analysis. As the spheres are arrange d in simple cubic array, the present numerical results are in good agr eement with the models predicated by Maxwell and also by Davis. In add ition, the simulation of porous media where spherical voids are arrang ed in tetragonal array is given to compare with the experimental inves tigation in the present study. Finally, the results show that the clea rance between two adjacent spheres in the direction of heat flow has a more pronounced effect on the effective thermal conductivities than t he other two directions as in an orthohombic structure.