Title: A visco-granular model of sedimentation in hydrogels

Author (Talk): Xavier Clotet, Clark University

Abstract:

Dense clay suspensions, commonly encountered in the petroleum industry, can show yield stress, thixotropy, shear thinning, and aging. This complex rheology can significantly affect settling properties of particles present in the system. However, it is difficult to distinguish the effect of the different properties of the fluid. We present sedimentation experiments of athermal particles in a simpler fluid, a granular suspension of hydrogels. Our results show that at the quasi-static limit the solution behaves like a dry frictional granular medium, while when it is sheared, a Herschel-Bulkley model describes its dynamics. This simpler suspension is a suitable model system to study sedimentation in visco-plastic fluids.