Experiments in shear flow of granular-fluid suspension and dense mixture

The feasibility of an innovative approach for the understanding of the rheology of granular-fluid mixtures involved sediment transport in water bodies is here analyzed. The results presented refer to an experimental work carried out using a pressure-imposed rheometer on mixtures composed by spherical uniform particles having different density dispersed into viscous interstitial fluids. The mechanics of flow of such materials have been studied by transferring the approach of dry granular media in terms of frictional rheology to wet suspensions. The shear stress as a function of the shear rate at imposed values of the normal stress has been measured. The data modeling show that the granular-fluid mixtures exhibit a viscoplastic behavior similarly to granular media successfully described by a frictional rheology and fully characterized by the evolution of the friction coefficient μ and the volume fraction Φ with a dimensionless viscous number Iv.