Fractal study on heat transport characteristics of spherical granular porous media with rough surfaces under different saturation conditions

Abstract

To explore the thermal transport characteristics of spherical media under different saturation states, the fractal model of thermal conductivity for porous media with rough surface spherical particles in saturated states and a thermal conductivity classification model in unsaturated states were established. The sensitivity fractal indicates that the thermal conductivity of spherical media is inversely proportional to the porosity, and solid matrix radius ratio, and directly proportional to the relative roughness, solid-liquid thermal conductivity ratio, and liquid saturation. Then, the proportion of thermal conductivity between the solid-phase matrix and liquid-phase pores was explored, and it was found that the thermal transport strength of spherical media mainly depends on the solid-phase matrix, and the relative roughness has a positive impact on the heat transfer of the matrix, while it has a negative impact on liquid-phase pores. Finally, the prediction results of the model are compared with the existing models and experimental data, and the accuracy and reliability of the model are verified. It shows that this new heat transfer model may better reveal the heat transfer characteristics of spherical Porous medium than the traditional model.