Comparison of experimental and simulated effective thermal conductivity of polymer matrix filled with metallic spheres: Thermal contact resistance and particle size effect

In this paper, we present a numerical and experimental study of a composite material with conducting spheres embedded in a polymer matrix. Our main objective is to study how the particle size and thermal contact affect the overall thermal properties of composites. In the numerical study, finite elements method is used to model heat transfer and to calculate the effective thermal conductivity. A periodical method was used to measure simultaneously thermal conductivity and diffusivity of the composite consisting of an epoxy resin matrix filled with brass spheres of different sizes. A comparison between the numerically calculated, measured and analytical thermal conductivity values for various samples is performed and the significance of the findings is discussed in the paper.