【摘要】 设计了一种新型磁悬浮轴流血泵,使用圆锥型磁轴承以避免由动静部件接触摩擦引起的血栓问题,其结构小巧紧凑并利于磁悬浮的实现.利用数值方法对血泵内的流场进行了模拟,加装出口导叶以改善血泵内部流场,得到了血泵的水力性能曲线及泵内压强、壁面切应力的分布.验证了转子和泵壳间的狭缝中存在与主流方向相反的逆向稳定冲刷流动,避免了狭缝内流动停滞,减少了血栓形成几率.给出了一种利用数值方法计算溶血指标的方法,并通过溶血指标的计算评价了血泵内的溶血程度,发现雷诺切应力是导致溶血的主要原因.更多还原

【Abstract】 A new axial blood pump with conical magnetic bearings was designed,which can avoid thrombus caused by contact between the rotating and stationary parts and whose compact structure makes it easier to realize the magnetic suspension.The flow field in the axial blood pump was investigated numerically,and the head-flow characteristics and the distributions of pressure and wall shear stress were analyzed.Calculation shows that there would be vortices shedding at the exit tube of the pump,which could be eliminated by adding guide vane at very downstream of the propeller.It is found that a steady backwards washout flow forms and no stagnation region is detected in the narrow gap between the rotor and the pump shell,and consequently the probability of thrombus formation decreases considerably in the gap.A numerical method to estimate hemolysis level in blood pump was presented and hemolysis indices were calculated.The results indicate that Reynolds shear stress is the major factor causing hemolysis in the blood pump.更多还原