Coal seam water injection is a widely used technique for dust suppression in coal mining. However, its effectiveness is often limited in low-permeability coal seams with poor wettability, primarily due to an unclear understanding of the wetting mechanism. To address this issue, a spontaneous imbibition model of a curved capillary bundle incorporating surface roughness elements was established based on the Hagen–Poiseuille equation. The accuracy of the proposed model was validated through experimental measurements, and the effects of different structural parameters on liquid imbibition behavior were systematically investigated. The results indicate that an increase in pore area fractal dimension significantly enhances the spontaneous imbibition capacity of water within coal pores. Moreover, the relative roughness inside pores increases with the minimum pore diameter, leading to a higher imbibition height. This suggests that increased relative roughness strengthens capillary attraction and promotes water migration in the pore structure. The proposed model provides a theoretical description applicable to the wetting stage of coal seam water injection and offers valuable insights for improving dust suppression efficiency in low-permeability coal seams.
Liu et al. (Sat,) studied this question.