Anisotropic fractal model for the effective thermal conductivity of random metal fiber porous media with high porosity

An anisotropic fractal model for the effective thermal conductivity (ETC) of random metal fiber porous media saturated in a low thermal conductivity fluid is proposed in this paper. The representative elementary volume (REV) was introduced. The cross section and the tortuous fiber in REV were considered as a fractal surface and a fractal curve respectively. The thermal tortuosity, maximum and minimum ETCs of REV were derived based on the fractal description under the assumption of one-dimensional heat conduction along the tortuous fractal fiber. The space angles between the REV and the heat flow direction were determined based on the experimental data to deduce the anisotropic ETC model of random metal fiber porous media with high porosity. The model prediction results have good agreement with the experimental data in literature.