Cheng Lizhi, Tan Jianping, Yun Zhong, Wang Shuai, Yu Zheqin
School of Mechanical and Electrical Engineering, Central South University, Changsha, China.
School of Mechanical and Electrical Engineering, Changsha University, Changsha, China.
Int J Artif Organs. 2021 Jan;44(1):46-54. doi: 10.1177/0391398820917145. Epub 2020 May 11.
To fully study the relationship between the internal flow field and hemolysis index in an axial flow blood pump, a computational fluid dynamics-discrete element method coupled calculation method was used. Through numerical analysis under conditions of 6000, 8000, and 10,000 r/min, it was found that there was flow separation of blood cell particles in the tip of the impeller and the guide vane behind the impeller. The flow field has a larger pressure gradient distribution, which reduces the lift ratio of the blood pump and easily causes blood cell damage. The study shows that the hemolysis index obtained by the computational fluid dynamics-discrete element method is 4.75% higher than that from the traditional computational fluid dynamics method, which indicates the impact of microcollision between erythrocyte particles and walls on hemolysis index and also further verifies the validity of the computational fluid dynamics-discrete element coupling method. Through the hydraulic and particle image velocimetry experiments of the blood pump, the coincidence between numerical calculation and experiment is analyzed from macro and micro aspects, which shows that the numerical calculation method is feasible.
为全面研究轴流血液泵内部流场与溶血指数之间的关系，采用了计算流体动力学-离散元法耦合计算方法。通过在6000、8000和10000 r/min条件下的数值分析，发现叶轮尖端和叶轮后方导叶处存在血细胞颗粒的流动分离。流场具有较大的压力梯度分布，这降低了血液泵的扬程比并容易导致血细胞损伤。研究表明，计算流体动力学-离散元法获得的溶血指数比传统计算流体动力学方法高4.75%，这表明红细胞颗粒与壁面之间的微碰撞对溶血指数的影响，也进一步验证了计算流体动力学-离散元耦合方法的有效性。通过血液泵的水力和粒子图像测速实验，从宏观和微观方面分析了数值计算与实验的吻合度，结果表明该数值计算方法是可行的。
