Liao Zhijie, Poh Churn K, Huang Zhongping, Hardy Peter A, Clark William R, Gao Dayong
Department of Mechanical Engineering, University of Kentucky, Lexington, KY 40506, USA.
J Biomech Eng. 2003 Aug;125(4):472-80. doi: 10.1115/1.1589776.
To develop a more efficient and optimal artificial kidney, many experimental approaches have been used to study mass transfer inside, outside, and cross hollow fiber membranes with different kinds of membranes, solutes, and flow rates as parameters. However, these experimental approaches are expensive and time consuming. Numerical calculation and computer simulation is an effective way to study mass transfer in the artificial kidney, which can save substantial time and reduce experimental cost. This paper presents a new model to simulate mass transfer in artificial kidney by coupling together shell-side, lumen-side, and transmembrane flows. Darcy's equations were employed to simulate shell-side flow, Navier-Stokes equations were employed to simulate lumen-side flow, and Kedem-Katchalsky equations were used to compute transmembrane flow. Numerical results agreed well with experimental results within 10% error. Numerical results showed the nonuniform distribution of flow and solute concentration in shell-side flow due to the entry/exit effect and Darcy permeability. In the shell side, the axial velocity in the periphery is higher than that in the center. This numerical model presented a clear insight view of mass transfer in an artificial kidney and may be used to help design an optimal artificial kidney and its operation conditions to improve hemodialysis.
为了开发更高效、更优化的人工肾，人们采用了许多实验方法来研究以不同类型的膜、溶质和流速为参数时，中空纤维膜内部、外部及跨膜的传质过程。然而，这些实验方法既昂贵又耗时。数值计算和计算机模拟是研究人工肾传质的有效方法，它可以节省大量时间并降低实验成本。本文提出了一种通过耦合壳侧、管腔侧和跨膜流动来模拟人工肾传质的新模型。采用达西方程模拟壳侧流动，采用纳维-斯托克斯方程模拟管腔侧流动，并使用 Kedem-Katchalsky 方程计算跨膜流动。数值结果与实验结果吻合良好，误差在 10%以内。数值结果表明，由于进出口效应和达西渗透率，壳侧流动中流速和溶质浓度分布不均匀。在壳侧，周边的轴向速度高于中心。该数值模型清晰地展示了人工肾中的传质情况，可用于帮助设计优化的人工肾及其运行条件，以改善血液透析效果。
