Effects of topological disorder in unsaturated granular media via a pore-scale lattice Boltzmann investigation

•We studied combined effects of topological disorder and wettability on multi-phase flow in wet granular media using pore-scale lattice Boltzmann simulations.•The increasing topological disorder can enhance the connectivity of liquid clusters, leading to a larger mean cluster volume and an early transition towards the funicular state from pendular state.•Correlations between the proposed capillary index, capturing effects from both topological disorder and wettability, and water retention curves are identified.