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.

摘要：

对高浓度的液固悬浮液在圆管中的流变特性进行了实验研究，实验体系为聚苯乙烯颗粒在NaCl水溶液中的中性悬浮液。测定了在层流状态下，固体颗粒的体积分数变化（20%～50%）、悬浮液流速变化（0.031～0.22 m•s^-1）以及颗粒粒度变化对悬浮液压降的影响规律。实验结果表明，固体颗粒的浓度会影响悬浮液的流变性质，颗粒粒径对悬浮液流变性影响微弱。悬浮液的压降随颗粒体积分数和流速的增大而增大，悬浮液的流动特性在较高颗粒浓度范围内符合幂率流体模型。