The Motion of Small Particles in Non-Newtonian Fluids

对颗粒在非牛顿流体中的运动进行了数值和实验研究。采用非线性弹性哑铃悬浮液模拟粘弹性流体。哑铃与宏观粒子之间的相互作用关系源于低雷诺数流体动力学。分析了各种参数的变化对多颗粒相互作用和流动的影响，包括松弛时间、剪切稀化和惯性。将模拟不同的流动条件、本构关系和典型应用，以获得关于该方法的适用性及其与各种物理流动系统的相关性的一般性结论。哑铃间的相互作用将使用快速多极子方法计算。核磁共振成像将用于测量沉积悬浮液和Couette设备中的粒子速度和浓度。所提出的数值方法适用于食品和石油工业、聚合物流动、塑料和其他材料加工中遇到的非牛顿流动。

The motion of particles in non-Newtonian fluids will be numerically and experimentally investigated. A suspension of non-linear elastic dumbbells is used to simulate viscoelastic fluids. The dumbbells interact with macroscopic particles via relationships derived from low-Reynolds-number hydrodynamics. The effect of changing various parameters on the multiple particle interaction and flow will be analyzed, including the relaxation time, shear thinning and inertia. Various flow conditions, constitutive relationships, and typical applications will be simulated in order to obtain generic conclusions on the applicability of the method and its correlation with various physical flow systems. Inter-dumbbell interactions will be calculated using the fast multipole method. Nuclear magnetic resonance imaging will be applied to measure particle velocity and concentration in sedimenting suspensions and in Couette devices. The proposed numerical approach has applications to non-newtonian flows encountered in food and petroleum industries, polymeric flows, plastics and other materials processing.