The Theory And Simulation Of Red Blood Cell Flow In Microvascular

The movement of the red blood cells (RBCs') in blood circulation, especially in the microvessel, has been one of the most important issues focused on recently. As the basic structure and basic function unit of the human circulatory system, microcirculation plays an important role in the whole blood circulation. So far, however, the studies about the flow characteristics of the blood and its impact on the vascular wall in microvascular are only take off.The outlines of the history and the development of the microcirculation f are given. The means used to analyse the movements of the microcirculation are reviewed, the purpose and the significance are elaborated then.After introduced the basic theory of the computational hydrokinetics and the blood flows, giving the basic model and the flow equations of the blood circulation, and analysing the deformability of the red blood cells, a certain model which is fitted to the characteristics of this research and the continuity equation and momentum equation are builded.Lattice Boltzmann method (LBM) is recognized as an alternative hydrokinetic computational method now, and its accuracy and robustness have been broadly confirmed. The applications include the numerical simulations of turbulent flows, two-phase flows, reaction-diffusion processes, granular and suspended particles. The LBM combined with the immersed boundary method (IBM) simulating the RBC movement in microcirculation is presented. The LBM is used to simulate the incompressible flow field, and the IBM is utilized to incorporate the solid-fluid interaction. The combination retains the advantages of the LBM in simulating different kinds of flows and provides a better approach to solve the solid-fluid boundary conditions.The interactions between the RBC and the blood plasma should be taken into consideration when the size of the RBCs is similar to the scale of the vessel in microcirculation. In many former literatures, the shape of the RBC is generally regarded as rigid or oval ball. The RBC is considered as biconcave liquid capsules here, while the membrane is represented by a set of points that move with the fluid points and external forces are induced on the fluid by adding a force term to the lattice Boltzmann equation. The blunt velocity profiles of the RBC flows are obtained, and the motion of the cell performs tumbling-rotating or tank-treading in the vessel. Nearly a circle of the deformation and movement of one single RBC is simulated.For further study of the RBC in blood flow, the finite element simulation software FLUENT is used to simulate the movement of the RBC moving along the axis of the blood flow. Both of the two-dimensional model and the three-dimensional model are established. Results obtained are excellent agreement with the existing medical experiments, which can prove that the methodology is effective.