基于动网格的永磁悬浮章动血泵流场数值模拟及溶血预测

Flow Field Numerical Simulation and Hemolysis Prediction of a Maglev Nutation Blood Pump Based on Dynamic Mesh

血泵转子高速旋转会造成血细胞出现不同程度的机械损伤,严重时可能危及患者生命,研究血泵流场特性是设计人工心脏泵的关键。以自主研发的章动磁悬浮血泵为例,基于计算流体动力学非定常三维N-S方程,采用标准κ-ε模型、用户自定义函数和动网格技术,模拟分析血泵内部流场情况,探究三维流场内速度、压力以及剪切应力大小及分布规律。建立磁悬浮章动血泵的溶血模型,采用粒子追踪法获取红细胞在血泵内所受剪切应力和暴露时间,预测血泵的溶血特性。研究结果表明血泵内部流动均匀,没有明显的回流和滞流现象,具有良好的血液相容性。研究为磁悬浮章动血泵的进一步优化设计和性能评价提供重要依据。

The high-speed rotation of the blood pump rotor will cause different degrees of mechanical damage to blood cells,which may endanger the lives of patients in severe cases. Studying the flow field characteristics of blood pump is the key to design an artificial heart pump. Taking the independently developed magnetic levitation nutation blood pump as an example,based on the unsteady three-dimensional Navier Stokes equations of computational fluid dynamics,the standard κ-ε model,user-defined function and dynamic grid technology are used to simulate and analyze the internal flow field of the blood pump.The distribution of velocity,pressure and shear stress in the three-dimensional flow field were explored. The hemolysis model of magnetic levitation nutation blood pump was established.The shear stress and exposure time of red blood cells in the blood pump were obtained by particle tracking method to predict the hemolytic characteristics.The results show that flow in the blood pump is uniform and no obvious separation or vortex occurs. The pump has a good biocompatibility. This study provides important basis for the further optimization design and performance evaluation of the maglev nutation blood pump.