The permeability of tree-like branching networks has long been a focus of academic research in fractal theory. Based on fractal theory, this study develops a permeability model for a damaged tree-like branching network that accounts for the influence of surface roughness. By incorporating key parameters such as relative roughness, damage degree, and number of branching levels, the model systematically characterizes the impact of the microstructure on fluid seepage. Meanwhile, Based on fractal theory, this study derives a fractal model for the dimensionless permeability of a porous medium composed of spherical particles and randomly distributed, rough tree-like branching networks embedded within it. Furthermore, the model incorporates an equivalent structure featuring conical corrugated pipes with expansion and contraction characteristics, systematically revealing the intrinsic relationships between the dimensionless permeability and key microstructural parameters such as porosity, fractal dimension, length ratio, diameter ratio, bifurcation angle of the branching network, and relative roughness. It is important to note that for porous media composed of conical pipes, as the inner diameter ratio increases, the dimensionless permeability decreases accordingly. This rule conforms to the physical laws in the field of fractal theory. Research suggests that randomly distributed, rough, and damaged tree-like branching networks can enrich and advance the physical studies of fluid flow in porous media.
ZHANG et al. (Sat,) studied this question.