| Summary: | 碩士 === 中原大學 === 土木工程研究所 === 93 === A numerical calculation procedure based on the least-squares finite element method (LSFEM) is employed to simulate flow field in abdominal aorta with two branches. In this paper, the two branches are considered either on the same side or on the opposite side of the artery. The baseline flow fields and the possible flow interaction between the two branches is major concerned in this study.
When the two branches are on the same side we found that the flow field and shear stress distribution are not quite similar to that in a single-branched tube while the two branches are distant and the interaction between the two branches weakened as the distance inside the branches increased. Also, in both the ventral part proximal to the first branch and the dorsal part distal to the first branch there exists low shear stress area.
When the two branches are on the opposite side the reversed flow regions are found on the lateral walls of the main tube. While the distance between two branches is zero is the most interesting case. In this case, both the flow field and the reversed flow region are symmetrical. As the distance between two branches increasing the reversed flow region extends from the upper sides proximal to the first branch to the lower sides distal to the second branch. The interaction of flow field becomes weaker when the distance between two branches is longer.
Based on the numerical simulation, it can be concluded that this numerical model can simulate the whole complicate flow domain in good agreement with the available simulates results and the observed experiments.
Keywords: Least-squares finite element method, shear stress, reversed flow regions, two branches flow
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