Computational fluid dynamic simulation of aggregation of deformable cells in a shear flow
Computational fluid dynamic simulation of aggregation of deformable cells in a shear flow
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DOI：
10.1115/1.2112907
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发表时间：
2005-12-01
影响因子：
1.7
通讯作者：
Popel, AS
中科院分区：
文献类型：
--
作者：
Bagchi, P;Johnson, PC;Popel, AS
我们对剪切流中两个可变形细胞的聚集进行了计算流体动力学（CFD）模拟。这项工作的动机是试图开发计算模型的聚集红细胞（RBC）。在生理和病理条件下，红细胞聚集是微循环中血液粘度的主要决定因素。红细胞的变形性在决定其聚集性中起主要作用。在宏观意义上，变形性取决于细胞质液的粘度和细胞膜的刚性。本文提出了一种计算研究红细胞聚集，考虑到流变学的细胞，以及细胞-细胞粘附动力学。这里考虑的模拟技术是二维的，基于前跟踪/浸没边界法的多种流体。这里介绍的结果是在两个细胞之间的聚集体形成的动态事件，其随后的运动，滚动，变形和破碎。我们发现，细胞的流变学性质有显着的影响的动态聚集体。在较高的细胞质粘度和膜硬度下形成稳定的聚集体。我们还表明，细胞之间形成的债券以循环的方式变化的聚集体在剪切流中滚动。循环行为与骨料的滚动取向有关。键数的振荡频率和振幅也取决于流变性质。
We present computational fluid dynamic (CFD) simulation of aggregation of two deformable cells in a shear flow. This work is motivated by an attempt to develop computational models of aggregation of red blood cells (RBCs). Aggregation of RBCs is a major determinant of blood viscosity in microcirculation under physiological and pathological conditions. Deformability of the RBCs plays a major role in determining their aggregability. Deformability depends on the viscosity of the cytoplasmic fluid and on the rigidity of the cell membrane, in a macroscopic sense. This paper presents a computational study of RBC aggregation that takes into account the rheology of the cells as well as cell-cell adhesion kinetics. The simulation technique considered here is two dimensional and based on the front tracking/immersed boundary method for multiple fluids. Results presented here are on the dynamic events of aggregate formation between two cells, and its subsequent motion, rolling, deformation, and breakage. We show that the rheological properties of the cells have significant effects on the dynamics of the aggregate. A stable aggregate is formed at higher cytoplasmic viscosity and membrane rigidity. We also show that the bonds formed between the cells change in a cyclic manner as the aggregate rolls in a shear flow. The cyclic behavior is related to the rolling orientation of the aggregate. The frequency and amplitude of oscillation in the number of bonds also depend on the rheological properties.