Magnetic resonance imaging of concentration and velocity profiles of pure fluids and solid suspensions in rotating geometries
Magnetic resonance imaging of concentration and velocity profiles of pure fluids and solid suspensions in rotating geometries
复制标题
旋转几何结构中纯流体和固体悬浮液的浓度和速度分布的磁共振成像
DOI：
10.1122/1.550724
复制
发表时间：
1995
影响因子：
3.3
通讯作者：
K. McCarthy
中科院分区：
文献类型：
--
作者：
A. Corbett;R. Phillips;R. Kauten;K. McCarthy
显示了聚甲基丙烯酸甲酯 (PMMA) 球体在聚亚烷基二醇 (PG) 中的体积百分比为 40% 的悬浮液的稳态和非稳态速度和浓度分布。这些轮廓是通过使用核磁共振成像（MRI）的非侵入性技术在三种实验几何结构中获得的：同轴旋转圆柱体（即，用于产生宽间隙库埃特流）、同轴圆柱体（其中直线螺纹随内圆柱体旋转并跨越表面之间的环形空间）以及单螺杆挤出机。浓度分布记录了同心圆筒装置和挤出机中颗粒从高剪切区域迁移到低剪切区域的情况。然而，直线圆柱体间隙上的浓度梯度并未表现出来，这表明混合在该几何形状中的相对重要性。纯 PG 流体和保持良好混合的悬浮液流的速度分布与牛顿流体预测的分布在数量上一致。
Steady and unsteady state velocity and concentration profiles are presented for a 40% by volume suspension of polymethyl methacrylate (PMMA) spheres in polyalkylene glycol (PG). The profiles were obtained by using the noninvasive technique of nuclear magnetic resonance imaging (MRI) in three experimental geometries: coaxial rotating cylinders (i.e., for generating wide‐gap Couette flow), coaxial cylinders in which a straight flight rotates with the inner cylinder and spans the annulus between the surfaces, and a single screw extruder. Concentration profiles document the presence of particle migration from high shear to low shear regions in the concentric cylinder apparatus and in the extruder. However, concentration gradients across the gap in the straight‐flight cylinder are not exhibited, indicating the relative importance of mixing in that geometry. Velocity profiles for the pure PG fluid and for suspension flows which remain well‐mixed agree quantitatively with profiles predicted for Newtonian fluids....