Rheology of red blood cell aggregation by computer simulation
Rheology of red blood cell aggregation by computer simulation
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DOI：
10.1016/j.jcp.2006.05.010
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发表时间：
2006-12-20
影响因子：
4.1
通讯作者：
Liu, Wing Kam
中科院分区：
文献类型：
--
作者：
Liu, Yaling;Liu, Wing Kam
由红细胞之间的相互作用诱导的红细胞（RBC）聚集是血液体外流变学性质的主导因素，并且现有的血液模型不包含完整的细胞信息。在这项工作中，我们引入了一个新的三维模型，耦合Navier-Stokes方程与细胞相互作用，研究红细胞聚集及其对血液流变学的影响。它由描述红细胞相互作用的耗尽介导聚集模型和跟踪血浆中红细胞变形/运动的浸入连续模型组成。为了克服红细胞的大变形问题，采用无网格方法对红细胞进行建模。通过这种方法成功地捕获和研究了血液流变学中的三个重要现象：血液粘度的剪切速率依赖性，细胞刚性对血液粘度的影响，以及Fahraeus-Lindqvist效应。作为血液粘弹性的剪切速率依赖性的微观说明，对在0.125和24 s（-1）之间变化的剪切速率下的RBC rouleau的解聚进行建模。较低的红细胞变形性和高于0.5 s（-1）的较高剪切速率被发现有利于解聚。模拟了不同剪切速率和不同变形能力的细胞的有效粘度。数值计算结果与实验测量结果一致。Fahraeus-Lindqvist效应首次通过不同直径的管中血流的三维数值模拟进行了研究，并被证明与可变形细胞的轴向迁移直接相关。本研究表明，细胞间相互作用和细胞变形性对毛细血管内血液流变学有重要影响。(c)2006年爱思唯尔公司All rights reserved.
The aggregation of red blood cells (RBC) induced by the interactions between RBCs is a dominant factor of the in vitro rheological properties of blood, and existing models of blood do not contain full cellular information. In this work, we introduce a new three-dimensional model that couples Navier-Stokes equations with cell interactions to investigate RBC aggregation and its effect on blood rheology. It consists of a depletion mediated aggregation model to describe the interactions of RBCs and an immersed continuum model to track the deformation/motion of RBCs in blood plasma. To overcome the large deformation of RBCs, the meshfree method is used to model the RBCs. Three important phenomena in blood rheology are successfully captured and studied via this approach: the shear rate dependence of blood viscosity, the influence of cell rigidity on blood viscosity, and the Fahraeus-Lindqvist effect. As a microscopic illustration of the shear-rate dependence of the blood's viscoelasticity, the disaggregation of an RBC rouleau at shear rates varying between 0.125 and 24 s(-1) is modeled. Lower RBC deformability and higher shear rates above 0.5 s(-1) are found to facilitate disaggregation. The effective viscosities at different shear rates and for cells with different deformabilities are simulated. The numerical results are shown to agree with the reported experimental measurements. The Fahraeus-Lindqvist effect is, for the first time, studied through three-dimensional numerical simulations of blood flow through tubes with different diameters and is shown to be directly linked to axial-migration of deformable cells. This study shows that cell-cell interaction and cell deformability have significant effects on blood rheology in capillaries. (c) 2006 Elsevier Inc. All rights reserved.