Critical State Flow Rules for Cfd Simulations of Wet Granular Flows

Abstract. First rheological investigation results of weakly wet granular media are presented. The materials have been examined experimentally and numerically in welldefined shear configurations in steady state, in the intermediate flow regime. For the experiments, a Searl-type ring shear cell with rotating inner cylinder and fixed outer cylinder is used. In the numerical particle simulation approach, a split-bottom shear cell is used. Relevant local continuum flow fields (e.g. velocity, stress, shear rates) are determined by micro-macro transition from the simulations data. After the simulations are validated by experiments, e.g. by comparison with the experimentally accessible quantities like shear-torque at the inner wheel, they can give a deeper insight into the microscopic kinematics. The granular media have considerably more “wet contacts” in the shear zone, as for example the location-plot of purely wet bridges, without mechanical contacts suggests. Finally, critical state flow rules concerning the viscosity of wet granular materials are discussed.