Fractal Study on the Effective Thermal Conductivity of Rough Dual-Porosity Media

Heat transport in dual-porosity media is ubiquitous in fields such as energy, materials science, and biology. Currently, most studies on thermal conductivity typically consider only the single pore structure of either the matrix or the fracture network, while research that jointly considers heat transport in dual-porosity media of both the matrix and fracture network often neglects the roughness of the channel surfaces. Based on Fourier's Law, this paper establishes a fractal model for the effective thermal conductivity of dual-porosity media with rough surfaces and explores the impact of relative roughness and other microstructure parameters on the heat transport process. The research results indicate that the dimensionless effective thermal conductivity of dual-porosity media is negatively correlated with relative roughness and the bifurcation level of the fracture network, while it is positively correlated with the fractal dimension of both the fracture network and matrix pores, as well as the ratio of the thermal conductivity of the fluid phase to the solid phase. To validate the effectiveness of the model, this study compares the predicted results with existing experimental data, showing good agreement.