离心式心脏泵内部流场的定常与非定常数值模拟

发布时间：2018-04-22 03:10

本文选题：离心式心脏泵 + 流场　；参考：《兰州理工大学》2012年硕士论文

【摘要】：随着科学技术的进步和经济的发展，应用人工心脏泵代替自然心脏的心脏病患者越来越多。离心式心脏泵作为一种新型的人工心脏泵，具有体积小、可靠性高，对血液破坏性小等优点，它的研究对心脏泵的发展有很重要的作用。本课题利用CFD软件对采用一元理论设计方法所设计的离心式心脏泵进行定常和非定常数值计算，模拟和分析了离心式心脏泵内部流场的分布，研究了泵内部流动的特殊规律和流动机理。分别用定常和非定常的方法模拟分析了离心式心脏泵在不同转速和流量下的内流场的压力场、速度场、速度矢量和切应力等的分布，，为离心式人工心脏泵提高性能以及抗血栓和溶血提供了依据。本文综合分析了国内外人工心脏泵的研究现状，并阐述了CFD的基本理论，介绍了CFD软件模拟过程中所用到的模型及数值计算方法。利用PRO/E软件建立三维流道实体模型，将三维流道实体模型导入网格划分软件ICEM，利用四面体非结构化网格分别对吸入室、叶轮、蜗壳以及回流区进行网格划分，并分析了网格数量及质量对数值解的影响。利用CFD软件FLUENT对得到的四部分网格文件进行合并，设置流场计算的参数和边界条件，采用RNGkε湍流模型和压力耦合的SIMPLEC算法求解方程，实现了人工心脏泵流场的定常和非定常数值模拟。对不同工况下的心脏泵进行定常数值模拟，得到了离心式心脏泵的外特性曲线以及内流场的压力、速度以及切应力等的分布；对设计工况下的心脏泵进行非定常数值模拟，研究了心脏泵的轴向力、径向力以及速度和压力分布，揭示了离心式心脏泵叶轮和蜗壳的动静干扰对流体产生的非定常影响。从模拟结果可以看出心脏泵内的速度场与压力场的分布与理论研究相一致。研究结果可以对后续的研究以及离心式心脏泵的选型提供参考。
[Abstract]:With the progress of science and technology and the development of economy, more and more heart disease patients are used in replacing natural heart with artificial heart pump. As a new type of artificial heart pump, centrifugal pump has the advantages of small volume, high reliability and small destruction to blood. The research of centrifugal pump plays an important role in the development of heart pump.
Using the CFD software, the centrifugal heart pump designed by the one element theory design method is used for the constant and unsteady numerical calculation. The distribution of the internal flow field of the centrifugal pump is simulated and analyzed. The special law and flow mechanism of the internal flow of the pump are studied. The centrifugal type is simulated and analyzed by the constant and unsteady methods. The distribution of the pressure field, velocity field, velocity vector and shear stress of the inner flow field of the heart pump at different speed and flow rate provides the basis for the improvement of the performance of the centrifugal pump and the anti thrombus and hemolysis.
This paper comprehensively analyzes the current research status of artificial heart pump at home and abroad, expounds the basic theory of CFD, introduces the model and numerical calculation method used in the process of CFD software simulation, and uses PRO/E software to establish a three-dimensional flow entity model, and introduces the three-dimensional flow entity model into the grid division software ICEM, and uses the tetrahedral unstructured network. Grids are meshed in the suction chamber, impeller, volute and reflux area respectively, and the influence of the number and quality of the grid on the numerical solution is analyzed. The parameters and boundary conditions of the flow field calculation are set up by using the CFD software FLUENT, and the RNGk e turbulence model and the pressure coupled SIMPLEC algorithm are used to solve the problem. The steady and unsteady numerical simulation of the flow field of the artificial heart pump is realized.
The external characteristic curve of the centrifugal pump and the distribution of the pressure, velocity and shear stress of the inner flow field are obtained by the constant numerical simulation of the heart pump under different working conditions. The unsteady numerical simulation of the heart pump under the design condition is carried out. The axial force, radial force, velocity and pressure distribution of the heart pump are studied, and the separation of the heart pump is revealed. The unsteady effects of the static disturbance on the flow of the heart pump impeller and the volute on the fluid production. From the simulation results, the distribution of the velocity field and pressure field in the heart pump is consistent with the theoretical study. The results of the study can provide a reference for the follow-up study and the selection of centrifugal pump.

【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH311

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