血液流經人工器官如血泵、人工心瓣、氧合裝置等，會在心血管中，形成非生 理性的紊流，而紊流所產生的血流應力，會造成紅血球的破壞，而引發溶血的 併發症。過去的研究認為紊流場中的雷諾應力值是血球破壞的指標。近來則認 為僅有在相近於血球尺寸的紊流場漩渦尺度所產生的黏滯切應力，才是血球破 壞的主要機械力。由於受限於儀器的時間與空間解析度，無法量測血球大小之 黏滯應力，因此除了模型的數值計算外，無人針對紊流尺度與血球破壞的影響 做實際的實驗探討。本研究將利用軸對稱的噴射流所產生的剪力紊流場，進行 血球破壞的實驗，將使用質點流速儀進行流場的量測，並採用次格點尺度的方 法推算，以求得近似血球大小的黏滯切應力，並注入猪血的血球至量測已知的 黏滯切應力及尺度位置，以探討紊流尺度大小與血球破壞的影響。 As blood flows through artificial devices, such as blood pumps, prosthetic heart valves, and oxygenators, non-physiologic turbulent flow is created. Consequently, hemodynamic stresses on blood components, specifically red blood cells, may lead to hemolysis. Previous research has used the Reynolds shear stress as an indicator for hemolysis, but more recent studies support the thought that the primary mechanical hemolytic force is the viscous shear stress created by turbulent eddy scales that are similar in size to red blood cells. Regarding this topic, researchers have been limited to computational models in the determination of viscous shear stresses on the scale of red blood cell sizes due to the limitations of the temporal and spatial resolutions of current instruments. We propose the study of viscous shear stresses of a shear layer generated by an axisymmetric jet flow. The flow will be measured with particle image velocimetry, the viscous shear stresses will be calculated with the sub-grid-scale method. After the degree of viscous shear stress and eddy locations have been determined, porcine blood components will be introduced into the flow field to further determine the relationship, if any, between turbulent scale size and blood cell damage.
