Multi-scale simulation of granular flows

Granular flows can be solved with numerical simulations. Via the MigFlow software, a numerical simulation project, a better understanding of the viscoelastic properties of suspensions can be provided. In the aim of this thesis, we simulated a simple shear in order to analyze the viscosity curve as a function of the compacity. By realizing that MigFlow computed wrong results, we worked on the modification of the software to obtain results in agreement with the models of the literature. Moreover, a parametric study was performed to observe the influence of the friction coefficient and the shear rate on the viscosity. The normal forces applied by the grains on the domain boundaries were also discussed. Furthermore, a frequency analysis was performed to evaluate the stress response of the flow to a sinusoidal deformation. These last results were compared to scientific literature data to assess their consistency with the reality. Finally, the complex shear modulus was studied and confirmed by the literature. We notice that there are still some errors which means that the exact physical properties are not accurately obtained. But in general the results are quite consistent with reality, which is promising for the project.