为解决血泵因叶顶间隙泄漏而造成溶血和血栓等问题,引入了一种折边不等间距叶轮,采用计算流体力学(computational fluid dynamics,CFD)进行内部流场的数值模拟,并与非折边不等间距叶轮及折边等间距叶轮进行对比分析,研究了它们的内流场动力学特性和血液相容性.结果表明:折边叶片结构血泵避免了叶顶间隙泄漏流的产生,同时折边不等间距叶轮减少了叶轮入口和出口处的回流和涡流,流道内整体切应力低于其他 2 种叶轮;3 种叶轮的溶血指数HI均满足血泵的溶血设计指标,其中,折边不等间距叶轮血泵壁面切应力在 0～150 Pa 的占比达96.84%,曝光时间相对集中且满足人工血泵设计要求,溶血指数较非折边不等间距叶轮血泵下降了 3.50%,较折边等间距叶轮血泵下降了12.50%,溶血性能最优.提出的折边不等间距叶轮血泵可有效降低红细胞破损概率,减少溶血和血栓的发生,可为轴流血泵的结构设计和优化提供一定参考.
Numerical simulation and hemolysis analysis of aortic puncture type axial flow blood pump impeller with folded-edge structure
In order to solve the problems of hemolysis and thrombosis caused by tip clearance leakage in axial flow blood pumps,a folded-edge unequally spaced impeller was introduced first,then CFD technology was used to simulate the internal flow field dynamic characteristics and blood compatibility.In addition,the results were compared with that of the non-folded-edge unequally spaced impeller and folded-edge equally spaced impeller.The results show that the blood pump with folded-edge impeller structure avoids the generation of leakage flow in the tip gap of the impeller,while the folded-edge unequally spaced impeller reduces the backflow and vortex at the inlet and outlet of the impeller,and the overall shear stress in the flow channel is lower than the other two impellers.The hemolysis index(HI)of all three impellers meets the hemolysis design index of the blood pump,in which the percen-tage of the wall shear stress of the blood pump with folded-edge unequally spaced impeller in the range of 0-150 Pa reaches 96.84%,the exposure time is relatively concentrated and the design requirements of an artificial blood pump are met.The hemolysis value decrease by 3.50%and 12.50%,respectively,while compared with blood pump with non-folded-edge unequally spaced impeller and fol-ded-edge equally spaced impeller,and the hemolysis performance is optimal.The proposed blood pump with folded-edge unequally spaced impeller can effectively reduce the probability of red blood cell breakage and the occurrence of hemolysis and thrombosis,which can provide reference for the structural design and optimization of axial flow blood pumps.
国家科技期刊平台
NSTL
万方数据
维普
