MECHANICS

Analytical models of thermal conductivity in two-phase dispersion media. 2. Comparison of theoretical and experimental data

B. V. Boshenyatov^a, A. A. Glazunov^b, A. N. Ishchenko^b, Yu. N. Karnet<sup>a

a</sup> Institute of Applied Mechanics of the Russian Academy of Sciences, Moscow, Russian Federation
^b Tomsk State University, Tomsk, Russian Federation

Abstract: It is traditionally believed that theories and formulas for averaging (homogenization) the physical properties of dispersion media, which exclude the effect of the collective interaction of dispersed particles, are applicable only at low concentrations of the dispersed phase. This opinion was disapproved theoretically and then experimentally in a previous paper. It has been established that with an increase in the concentration of dispersed particles, the main effect on the change in the effective thermal conductivity coefficient of the dispersion medium is exerted by the purely geometric factor of compaction of dispersed particles. Therefore, if the experimental conditions correspond to the theoretical premises considering a two-phase medium as homogeneous and isotropic and the dispersed particles as isolated from each other, then Maxwell's analytical formula is applicable (with an error of less than 2.7%) over the entire range of variation of concentrations and phase parameters. It is shown that the proposed new analytical dependence, which is invariant with respect to the phase inversion transformation and does not take into account the interaction of particles, best describes experiments in binary metal mixtures when it is impossible to isolate a continuous dispersed phase.

Keywords: dispersion media, composite materials, interaction of dispersed particles, Laplace's equation, effective thermal conductivity coefficient.

UDC: 536.2; 544.012

Received: 19.09.2023

DOI: 10.17223/19988621/91/6