Abstract:

The rheological properties of moderately concentrated suspensions were studied experimentally.This work was focused on the systems consisting of rigid，neutrally buoyant spheres suspended in a Newtonian fluid undergoing laminar tube flow.The frictional pressure drop was measured as a function of non-Newtonian power-law constants.The particle holdups of the suspensions were from 20% to 50%，and the flow rates ranged from 0.031 m•s^-1 to 0.22 m•s^-1 to ensure the laminar flow condition.The effects of solid concentration and flow rate on the rheological properties of the suspension were examined.With the increase of particle concentration and flow rate，a substantial increase in pressure drop of the suspension was observed.The particle size seemed to have little influence on the rheological behavior of neutrally buoyant suspensions.The rheological behavior of suspensions at a high solid concentration is correlated by a power-law fluid model.