以數值方法模擬三維同側及不同側分岔血管流場及質傳現象

Numerical simulation of flow field and mass transfer with branches on the same and different sides of the artery

邱梅君(Mei-Jun Qiu)

指導教授 ： 鄧志浩

中原大學/工學院/土木工程研究所/碩士(2007年)

https://doi.org/10.6840/cycu200700065

摘要

摘 要
本研究為兩分岔血管位於腹主動脈管的流場模擬，過程中是利用最小平方有限元素法（LSFEM）作為數值分析。在文中建立了兩分岔血管位於動脈同側及不同側兩種模型，並依著分岔血管之間不同的間距，觀察其速度向量、流線、剪應力及濃度分佈，探討兩分岔血管的流場和質傳現象。
在兩分岔血管位於同側的模型中，隨著分岔血管之間的距離增加其交互影響越低，兩分岔血管間的腹主動脈血管管壁上迴流區域也越小。質傳方面，分別在兩分岔血管中迴流現象造成低氧濃度的產生，此低氧濃度一直延伸至出口處。而腹主動脈血管管壁上迴流區域也產生低氧濃度，但此低濃度區隨著兩分岔血管間距離增加而遞減。另外，腹主動脈的背側腹側靠近第一根分岔血管前端有低剪應力產生。
在兩分岔血管位於不同側的模型中，腹主動脈血管管壁末端發現迴流區域產生。兩分岔血管間的距離為零時，流場與迴流區域呈對稱形式，隨著分岔血管之間的距離增加其交互影響減少。質傳方面，
腹主動脈血管管壁與兩分岔血管皆產生低氧濃度，且延伸至出口，隨著兩分岔血管間距離增加而遞減。最低剪應力發生在腹主動脈背側。
基於此數值模擬方式，本模式可有效處理整個複雜流場與質傳現象。
關鍵字：最小平方有限元素法、剪應力、質傳現象、迴流區域。

關鍵字

血管流場分析 ； 質傳現象

並列摘要

ABSTRACT
To simulate blood flow in two branches of abdominal aorta by the numerical analysis in applying the least-squares finite element method is studied in this paper. Two branches that are on the same and different sides of the blood artery are simulated. Based on the different distances of two branches, the mass transfer and flow field phenomena which include the distribution of velocity vector, the oxygen concentration, shear stress and streamline of two branches are observed.
For the model of two branches on the same side of the artery, the reversed flow and interaction region decreased in accompany with the increasing distances between two branches. As for mass transfer, in the reversed flow region inside the two branches the distribution of low oxygen concentration has extended to the exit section of the branches was found. But this low oxygen concentration region decreases in association with the increase of distances between two branches. 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.
As for the model of two branches on the different side of the main artery, the reversed flow region exists on the wall of abdominal aorta. While the distance between two branches is zero, both the flow field and reversed flow region are symmetrical. And the interaction decreased in accompany with the increasing distances between two branches. As for mass transfer, both the abdominal aorta walls and two branches show low oxygen concentration extended to exit section, and decreased accompanies the increasing distances of two branches. Also, in the dorsal part of abdominal aorta there exists low shear stress distribution.
Based on the numerical stimulation, we can effectively deal with the whole complicated flow field and mass transfer.

Keywords: Least-squares finite element method, shear stress, mass transfer, reversed flow region.

並列關鍵字

flow field ； mass transfer

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