红细胞在微小血管中的流动理论分析

发布时间：2018-06-11 21:05

本文选题：多块晶格波尔兹曼方法 + 前向跟踪法　；参考：《山东大学》2011年硕士论文

【摘要】：近几年,红细胞在微小血管中的流动分析问题,越来越受到人们的关注。微循环体系是人体血液循环系统中最基层的结构和功能单位,在整个血液循环中起重要作用,而微小血管作为微循环的主要组成部分,直接与组织细胞相接触,承载着主要的物质运输,但是迄今为止,有关此课题的研究还不多。由于该课题的可行性和重要性,作者对其进行了初步的综合理论分析。首先,本文对微循环流体力学的研究与进展进行了概述,阐述了微观流体力学的目的和意义,并对微观血液流变学数值研究的国内外发展状况和发展趋势做了简单回顾和介绍。其次,介绍了前向跟踪法(Front-tracking Method),又名界面追踪法的概念,解释了该方法的基本理论,并对其进行了总结与讨论,最后以举例的方式阐述了如何在红细胞研究中应用该方法。然后,对晶格Boltzmann方法进行了简介,详细介绍了晶格Boltzmann万法常用的边界条件,并对该方法进行了改进,使其更加适用于本文的模型。最后,给出了本文的模拟与仿真结果。在本文的模拟过程中,将前向跟踪法与晶格波尔兹曼法相结合来研究三维双凹碟形胶囊式红细胞的变形。将红细胞模拟为内含牛顿流体的双凹碟形弹性薄膜胶囊,薄膜内外的液体看做具有不同物理特性的流体,使用晶格波尔兹曼方法的多块策略改善细胞模型附近的网格,增加三维计算的准确度和效率。本文使用的细网格仅覆盖每个计算轴的40%,同时选用离散为连接4098个点的8192个三角元的细胞薄膜模型,不仅提高了网格分辨率,而且节省了计算时间；从理论上证明了在雷诺数不大于0.25的剪切流中,惯性作用对细胞变性的影响都很小；同时得到了无因次参数为0.05,细胞内外粘度比为0.2时三维健康红细胞的360°稳定坦克履行为。不仅成功模拟了惯性作用下典型的三维红细胞坦克履行为,而且使用的细网格仅占整个计算区域的6.4%,在保证计算准确度的同时提高了计算效率,为模拟三维红细胞变形提供了一种更加可行的途径。
[Abstract]:In recent years, more and more attention has been paid to the flow analysis of red blood cells in small blood vessels. The microcirculation system is the most basic unit of structure and function in the human blood circulation system, which plays an important role in the whole blood circulation. As the main component of the microcirculation, the tiny blood vessels are directly in contact with the tissue cells. It is carrying the main material transportation, but so far, the research on this subject is not much. Because of the feasibility and importance of this subject, the author makes a preliminary comprehensive theoretical analysis. Firstly, this paper summarizes the research and progress of microcirculation fluid mechanics, and expounds the purpose and significance of micro hydrodynamics. The development and development trend of micro hemorheology numerical research at home and abroad are briefly reviewed and introduced. Secondly, the concept of Front-tracking method, also known as interface tracking method, is introduced, and the basic theory of this method is explained. It is summarized and discussed, and how to apply this method in erythrocyte research is illustrated by an example. Then, the lattice Boltzmann method is briefly introduced, and the boundary conditions commonly used in lattice Boltzmann method are introduced in detail. The method is improved to make it more suitable for the model in this paper. Finally, the simulation and simulation results are given. In this paper, the forward tracking method and lattice Boltzmann method are combined to study the deformation of three dimensional double concave dish capsule red blood cells. The red blood cell is simulated as a double concave disc elastic film capsule containing Newtonian fluid. The liquid inside and outside the membrane is regarded as a fluid with different physical properties. The lattice Boltzmann method is used to improve the mesh near the cell model. Increase the accuracy and efficiency of 3D calculation. The fine mesh used in this paper covers only 40 parts of each axis, and a cell membrane model with 8192 triangles connecting 4098 points is selected, which not only improves the grid resolution, but also saves computing time. It is theoretically proved that in shear flow with Reynolds number less than 0.25, the effect of inertial action on cell denaturation is very small and the dimensionless parameter is 0.05 and the ratio of internal and external viscosity is 0.2. It not only successfully simulates the typical three-dimensional red blood cell tank under inertial action, but also uses a fine mesh that accounts for only 6.4of the whole calculation area, which ensures the accuracy of the calculation and improves the calculation efficiency. It provides a more feasible way to simulate three-dimensional erythrocyte deformation.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：R312

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