![]() Both the stresses T and P, as dimensionless groups Tσ D 2/λη 2, and Pσ D 2/λη 2, were found to bear single-valued empirical relations to a dimensionless shear strain group λ ½σ D 2(d U/d y)lη for all the values of λ< 12( C= 57% approx.) where d U/d y is the rate of shearing of the grains over one another, and η the fluid viscosity. ![]() ![]() ![]() The linear grain concentration λ is defined as the ratio grain diameter/mean free dispersion distance and is related to C by λ = 1 ( C 0 / C ) 1 2 − 1 where C 0 is the maximum possible static volume concentration. The dispersive pressure P was found to be proportional to a shear stress λ attributable to the presence of the grains. The torque on the inner drum was also measured. This was measured as an increase of static pressure in the inner stationary drum which had a deformable periphery. A substantial radial dispersive pressure was found to be exerted between the grains. The volume concentration C of the grains was varied between 62 and 13 %. The density σ of the grains was balanced against the density ρ of the fluid, giving a condition of no differential forces due to radial acceleration. Dispersions of solid spherical grains of diameter D = 0.13cm were sheared in Newtonian fluids of varying viscosity (water and a glycerine-water-alcohol mixture) in the annular space between two concentric drums.
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