轴流式血泵水动力特性和生物相容性的数值模拟  

Numerical Simulation for Hydrodynamics and Biocompatibility in an Axial Blood Pump

作　　者：胡其会[1] 张鸣远[1] 李景银[1] 杨万英[1] 

机构地区：[1]西安交通大学能源与动力工程学院,西安710049

出　　处：《西安交通大学学报》2011年第8期118-122,共5页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(50576074)

摘　　要：为了准确评价自行设计的轴流式血泵的水力性能和生物相容性,将一种黏弹性流体k-ε模型应用于该血泵内紊流流动特性的数值模拟,分析了轴流泵的泵壳与转子间狭缝中以及叶轮流道内的静压和切应力的分布规律,并将溶血指标计算方法与此黏弹性紊流模型结合,计算了黏弹性流体为工质时血泵的溶血指标,并与水为工质时的计算结果进行了对比.结果表明:在相同转速和流量条件下,质量分数为0.06%的黄原胶溶液为工质时的静压压升高于以水为工质时的相应值,质量分数为39%的甘油溶液为工质时静压压升最不明显;甘油溶液的雷诺应力和黏性切应力均高于水和黄原胶溶液的相应值;黏弹性流体为工质时泵的溶血指标比水和甘油溶液的低,且数值处于同一数量级上.该模型能较为准确地预测血泵内黏弹性流体的紊流流动特性,但血泵的结构需进一步优化和改善.To accurately evaluate the hydraulic performance and bioeompatibility of an axial blood pump designed and tested, a k-e model for viscoelastic fluids is employed to predict the turbulent flow characteristics in the pump. The distributions of static pressure and wall shear stress in the clearance gap between the rotor and the pump shell and in the main flow passage are analyzed. A numerical method for estimating hemolysis level in blood pump is used to calculate the hemolysis indexes of viscoelastic fluids and water. The simulation shows that the static pressure for 0. 06% （mass fraction） xanthan gum solution is higher than that for water at same flow rate and same ro tating speed, and the static pressure of 39% （mass fraction） glycerin solution is the lowest among them all. The Reynolds shear stress and the viscous shear stress for glycerin solution are higher than those for water and xanthan gum solution. The hemolysis index of viscoelastic fluids is lower than those of water and glycerin solution, and the hemolysis indexes of them all are in the same order of magnitude. This turbulence model can predict the turbulent flow characteristics of visco- elastic fluids in the pump accurately, and the structure of the axial blood pump is expected to be further optimized and improved.

关 键 词：黏弹性流体k-ε模型 轴流式血泵 数值模拟 溶血指标 

分 类 号：TH312[机械工程—机械制造及自动化]