Three-dimensional simulation of cohesive granular flows using lattice Boltzmann method with a μ(I)-rheology-based viscoplastic model

This paper introduces a novel three-dimensional numerical framework by combining the free-surface lattice Boltzmann method (LBM) with a μ(I)-rheology-based viscoplastic model for simulating cohesive granular flows. The proposed method aims to provide an accurate and efficient modelling of granular flow with a free-surface. In the present method, the evolution of the granular-air interface is modeled through a single-phase free-surface approach. A novel μ(I)-rheology-based viscoplastic model is used to describe the mechanical response of the granular material. We investigated the performance of the lattice Boltzmann method in conjunction with the μ(I)-rheology within a continuum framework, particularly examining how cohesion influences flow dynamics and the rheological properties of granular materials. A benchmark simulation of cohesive granular collapse is first presented, showing that the LBM results are in strong agreement with experimental data. The effect of aspect ratio on the final deposit shape and instability modes during column collapse is also verified. Finally, the sensitivity of the model’s parameters is assessed for the combined LBM and μ(I)-rheology approach. The findings demonstrate that the proposed LBM framework can accurately capture the flow characteristics of cohesive granular flows.