Summary: | 碩士 === 中原大學 === 土木工程研究所 === 86 === Intimal hyperplasia caused by the abnormal flow field near an end-to-side anastomosis may play in the failure of the bypass graft surgery. To carefully evaluate this hypothesis, a numerical analysis has been carried out to study the effect of the flow field near the anastomosis. In this research a numerical analysis was used to study the unsteady flow in a three dimensional end-to-side anastomosis. Based on the study of the three dimensional flow field near the end-to-side anastomosis, the geometry change may cause abnormal flow field such as recirculating zones, high shear stress gradients and secondary flow. The abnormal flow field may cause the intimal hyperplasia which leads to occlusion of the graft lumen. In addition, secondary flow has a great influence in the flow field. The result of a two dimensional model can''t represent the overall phenomena in a three dimensional model. For real human artery the blood flow is unsteady, so the result of numerical simulation of a three dimensional unsteady model was considered to be more reasonable than that of the three dimensional steady one.
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