毛细血管中红细胞流变特性的基础性研究

发布时间：2018-05-24 03:04

本文选题：格子Boltzmann方法 + 定向粒子　；参考：《山东大学》2012年硕士论文

【摘要】：作为给机体组织传输氧气的主要途径,红细胞在所有脊椎动物和一些非脊椎动物中扮演者非常重要的角色,从生物角度上看,一个健康的人类红细胞常态下是双凹面蝶形的液态胶囊状,最大直径接近于毛细血管的直径。当红细胞穿过毛细血管的时候会遭遇血流的阻力,从而导致红细胞发生形变。红细胞变形功能是否正常直接与一些血液疾病相关,因此,研究毛细血管微循环中红细胞的运动与变形,揭示红细胞运动行为的机理,可以为相关的血液疾病提供非常有价值的理论知识。一方面,本文总结了微循环中红细胞机械行为研究的很多经验、理论以及数值方法。根据毛细血管微循环的特殊性,对各种数值方法的优、缺点进行分析对比。提出了一种格子Boltzmann方法与水平集方法相结合的数值方法对毛细血管微循环血流模拟仿真,并详细论述了该数值方法的原理,验证了该方法的合理性与高效性。另一方而,通过仿真实验得到的数据,分析了血流的各种基本量对红细胞运动变形的影响,如红细胞半径、粘滞度和密度等,观察了红细胞的聚合与离散行为,得出毛细血管微循环血流中红细胞在不同血液流体环境中运动变形的相关结论。在本文的仿真中,将毛细血管壁模拟为刚性直圆管,红细胞模拟为内含不可压缩的牛顿流体的双凹面碟形弹性薄膜胶囊,毛细血管微循环血流环境模拟为具有不同性质、不可压缩的单相流体,并且该单相流的流动状态为层流,满足边界无滑移条件。本文使用Navier-Stokes方程作为运动控制方程,并在微观上使用格子Boltzmann方程描述其运动。另外,本文将利用定向粒子修正的局部水平集方法追踪由流体性质不连续而存在边界。将格子Boltzmann方法与水平集方法结合起来,模拟红细胞在毛细血管微循环中运动,为红细胞在毛细血管微循环中的运动的研究和与红细胞有关的临床医学提供了理论参考。
[Abstract]:Red blood cells play a very important role in all vertebrates and some non-vertebrates as the main way to transport oxygen to the body's tissues, from a biological point of view. A healthy human red blood cell is normally a double concave butterfly-shaped liquid capsule with a maximum diameter close to the diameter of the capillaries. When red blood cells pass through capillaries, they encounter resistance to blood flow, which causes red blood cells to deform. Whether the function of erythrocyte deformability is normal is directly related to some blood diseases. Therefore, to study the movement and deformation of red blood cells in capillary microcirculation and to reveal the mechanism of erythrocyte movement behavior, It can provide valuable theoretical knowledge for related blood diseases. On the one hand, this paper summarizes many experiences, theories and numerical methods in the study of erythrocyte mechanical behavior in microcirculation. According to the particularity of capillary microcirculation, the advantages and disadvantages of various numerical methods are analyzed and compared. In this paper, a numerical simulation method of capillary microcirculation is presented, which combines the lattice Boltzmann method and the level set method. The principle of the numerical method is discussed in detail, and the rationality and efficiency of the method are verified. On the other hand, through the data obtained from the simulation experiment, the effects of various basic blood flow quantities on the erythrocyte movement deformation, such as the red blood cell radius, viscosity and density, were analyzed, and the aggregation and dispersion behavior of the red blood cells were observed. The conclusion of the red blood cell movement and deformation in different blood fluid environment in capillary microcirculation is obtained. In the simulation of this paper, the capillary wall is simulated as a rigid straight tube, the red blood cell is simulated as a double concave disc elastic film capsule containing incompressible Newtonian fluid, and the blood flow environment of capillary microcirculation is simulated as having different properties. The incompressible single-phase fluid, and the flow state of the single-phase flow is laminar, satisfying the boundary non-slip condition. In this paper, the Navier-Stokes equation is used as the governing equation of motion, and the lattice Boltzmann equation is used to describe the motion of the equation. In addition, the local level set method modified by directional particles will be used to trace the existence of boundary due to discontinuity of fluid properties. The lattice Boltzmann method is combined with the level set method to simulate the movement of red blood cells in capillary microcirculation, which provides a theoretical reference for the study of the movement of red blood cells in capillary microcirculation and the clinical medicine related to red blood cells.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R312

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