Keynton R S, Rittgers S E, Shu M C
Department of Biomedical Engineering, University of Akron, OH 44325.
J Biomech Eng. 1991 Nov;113(4):458-63. doi: 10.1115/1.2895427.
A steady flow, in vitro model of distal arterial bypass graft junctions was used to examine the effects of junction angle and flow rate on the local velocity field. Three test sections were fabricated from Plexiglas tubing having anastomotic junction angles of either 30, 45, or 60 deg. Flow visualization revealed velocity profiles skewed toward the outer wall with a flow split around a clear stagnation point along the outer wall. Laser Doppler anemometry [LDA] measurements confirmed a distinct stagnation point at the outer wall and both reverse and forward shear were detected immediately upstream and downstream, respectively, of this site. Axial velocities and shear rates along the outer wall were higher than along the inner wall and occurred in the junction angle order: 45, 60, and 30 deg. This study clearly identified changes in wall shear which varied with the anastomotic angle and flow rate.
使用一种稳定流的体外远端动脉搭桥移植物连接模型来研究连接角度和流速对局部速度场的影响。三个测试段由有机玻璃管制成，其吻合连接角度分别为30度、45度或60度。流动可视化显示速度剖面偏向外壁，在沿外壁的一个清晰停滞点周围出现流动分流。激光多普勒测速仪（LDA）测量证实在外壁处有一个明显的停滞点，并且分别在该点的紧邻上游和下游检测到反向和正向剪切。沿外壁的轴向速度和剪切率高于沿内壁的，并且按照连接角度顺序出现：45度、60度和30度。这项研究清楚地确定了壁面剪切的变化，其随吻合角度和流速而变化。
