本研究以二維優化後的ASV-1翼型為截面形狀，建構出一三維的翼型人工心瓣，並利用計算流體力學的方法來進行葉瓣在主動脈血管流場數值模擬，以分析三維翼型人工心瓣的血液動力特性。因三維翼型瓣為一低展旋比外型，會形成翼前緣渦流(Leading-Edge Vortices)，這兩對稱渦流對流場會造成相當大的三維效應，而使二維與三維流場產生明顯的差異。翼前緣渦流會將管流外部高速流體捲入葉瓣背風面(leeside)的尾流區，因此強化了分離區的流體動能而減少了血栓生成的可能性。本研究中尋找出的三維翼型人工心瓣的最佳旋轉中心位置為0.325c，與二維流場的位置略有不同。此旋轉中心位置的修正除可獲得接近靜平衡最大開孔角合力矩之外，同時也可減少全壓損耗(Total Pressure Loss)。為了增加翼型瓣的翼後緣(Trailing Edge)結構強度，在翼後緣部位做倒圓角(Rt.e.=0.05c)的修正，此修正不致對整個流場的血動力(Hemodynamics)特性產生太大的影響。與平板心瓣相比，修正過後的翼型瓣在三維流場中，血液通過葉瓣時的壓力損耗低，駐留區小，雷諾應力與血管壁剪應力皆低，因而較不易產生血栓現象。本研究證實以翼型曲線外型作為人工心瓣外型，的確可以改進人工心瓣血管流的血動力特性。

A three-dimensional (3D) Aero-Shaped-Valve was designed by using the previously optimized two-dimensional (2D) ASV-1 configuration as the sectional shape. Computational Fluid Dynamics was employed to analyze this ASV aorta flow to see whether hemodynamic properties can be improved as concluded previously in the 2D optimization. The 3D ASV occluder is a low aspect-ratio configuration, which may generate leading-edge vortices that are not seen in the 2D ASV-1 flow. High-speed fluid particles were entrained into the low-speed separation zone, hence greatly energize the stagnant, recirculatory leeside flowfield of the occluder. This vortex-induced mixing effect is the main 3D mechanism that reduces the possibility of thrombus formation. In the present 3D study, the zero-moment rotation center was found to be located at the 0.325c position, which, in the main time, can reduce the total pressure loss as compared to that using the 2D optimized rotation center position. The trailing-edge of the 3D ASV occluder was modified using a rounded trailing-edge (Rt.e.=0.05c) to strengthen the structural integrity. It was found that this trailing-edge modification does not change the flow properties significantly. Comparing to the convectional plate-like occluder, the hemodynamic characteristics can be improved in terms of lower total pressure loss, smaller stagnation region, reduced turbulent Reynolds stresses and wall shear stress for the ASV occluder design. Occluder configuration is hence justified critical to the heart valve design and hemodynamics can be significantly improved as airfoil-like shapes are considered.

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