Quantitative visualization of flow through a centrifugal blood pump: effect of washout holes.
Quantitative visualization of flow through a centrifugal blood pump: effect of washout holes.
复制标题
通过离心血泵的流量的定量可视化：冲洗孔的影响。
作者：
M. Nishida;T. Yamane;T. Orita;B. Asztalos;H. Clarke
为了阐明冲洗孔对离心血泵中流动的影响以防止血液停滞，应用定量流动可视化技术来比较有和没有冲洗孔的模型中的流动。采用高速摄像机和粒子跟踪测速仪对流场图像进行了处理，并对流场进行了模拟。特别注意通过叶轮前后间隙的流动。结果表明，在叶轮后的差距中，冲刷孔不仅使叶轮内流，而且使切向速度增加。在叶轮前面的差距中，冲洗孔引起向外流动和切向速度的减小。在初始设计中，水头流量特性几乎不受冲洗孔的影响，其中通过冲洗孔的流量设定为外部回路中流量的约10%。这些结果表明，通过冲洗孔的流动是显着的，在防止血液停滞的两个方面。首先，叶轮后面的向内径向速度和叶轮前面的向外速度导致流体交换，其次，切向速度增加减少了叶轮后面的流体停滞。
To clarify the effect of washout holes on the flow in a centrifugal blood pump to prevent blood stagnation, a quantitative flow visualization technique was applied to compare flows in models with and without washout holes. A scaled-up model of a prototype pump and a high speed video camera were used for the flow visualization, and images were processed by particle tracking velocimetry. Particular attention was paid to the flow through the gaps behind and in front of the impeller. The results showed that in the gap behind the impeller, washout holes caused not only an inward flow, but also an increase in the tangential velocities. In the gap in front of the impeller, washout holes caused an outward flow and a decrease in the tangential velocities. Head flow characteristics were little affected by the washout holes in this initial design for which the flow through the washout holes was set to be approximately 10% of the flow in the external circuit. These results suggest that the flow through washout holes is significant in the prevention of blood stagnation in 2 ways. First, the inward radial velocity behind the impeller and outward velocity in front of the impeller result in fluid exchange, and second, a tangential velocity increase reduces fluid stagnation behind the impeller.