Rheology of solid-liquid suspensions in reduced gravity

Viscosity of settling suspensions was studied experimentally in a series of reduced gravity parabolic flights aboard NASA's KC-135 aircraft. Slurries were made using silica sand (0.150 mm < d(p) < 0.212 mm) and glycerol solut ion. The experimental set-up incorporated instrumentation to measure the ap parent viscosity of the sand suspensions at the wide range of the shear rat es. The container had transparent walls to allow visualization of the struc ture changes involved in Couette flow in reduced gravity. Experiments were performed over a broad range of gravitational accelerations including micro gravity and double gravity conditions. The results of the flight and ground experiments reveal significant differences in the apparent viscosity of sa nd suspensions and overall void factor in microgravity as compared to l-G c onditions. (C) 1999 Elsevier Science S.A. All rights reserved.