Spiral wound membrane modules operate as filtration modules in the food, beverage, and pharmaceutical industries. As many fluids are non-Newtonian or become non-Newtonian during concentration, it is essential to gain an understanding of the effect of a shear-rate dependent viscosity. This computational work examines the impact of the fluid rheology and the Reynolds number on the hydrodynamics and the mass transfer in zigzag and cavity spacer-filled channels under laminar flow conditions. To describe the rheology of the working fluid, we utilized the well-known power-law model. The power-law index values corresponded to 0.7, 1, and 1.3, representing shear-thinning, Newtonian, and shear-thickening behavior, respectively. The Reynolds number was varied up to 160 whereas the Schmidt number was kept constant at 500. A standard convection–diffusion equation with a constant wall concentration was employed to describe the mass transfer. In agreement with previous works on Newtonian fluids, the zigzag spacer was found to be the most promising spacer type, because of the enhanced mass transfer in the reattachment regions. Whereas the mass transfer was only slightly affected by the rheology, the shear thinning fluid produced the smallest pressure drop. As a direct consequence of the positive effect on the pressure drop, the spacer efficiency was highest in all configurations. The results of this first numerical investigation in the context of non-Newtonian fluid flow through spacer-filled channels emphasize the importance of taking into account a varying fluid viscosity in the design and operation of the filtration process.

螺旋缠绕膜组件在食品，饮料和制药行业中用作过滤组件。由于许多流体在浓缩过程中是非牛顿流体或变为非牛顿流体，因此必须了解剪切速率相关粘度的影响。这项计算工作检查了层流条件下流体流变学和雷诺数对之字形和空腔填充通道中流体动力学和传质的影响。为了描述工作流体的流变性，我们利用了众所周知的幂律模型。幂律指数值分别对应于0.7、1和1.3，分别表示剪切变稀，牛顿和剪切变厚行为。雷诺数最大变化到160，而施密特数保持恒定在500。使用具有恒定壁浓度的标准对流扩散方程来描述传质。与先前有关牛顿流体的研究一致，之字形垫片被认为是最有前途的垫片类型，因为其在重新附着区域的传质增强。尽管传质仅受流变学的轻微影响，但剪切稀化流体产生的压降最小。作为对压降产生积极影响的直接结果，隔离器效率在所有配置中均最高。在通过隔板填充通道的非牛顿流体流动的背景下，第一个数值研究的结果强调了在过滤过程的设计和操作中考虑变化的流体粘度的重要性。