Perktold K, Resch M, Florian H
Institute of Mathematics, Technical University Graz, Austria.
J Biomech Eng. 1991 Nov;113(4):464-75. doi: 10.1115/1.2895428.
Numerical analysis of flow phenomena and wall shear stresses in the human carotid artery bifurcation has been carried out using a three-dimensional geometrical model. The primary aim of this study is the detailed discussion of non-Newtonian flow velocity and wall shear stress during the pulse cycle. A comparison of non-Newtonian and Newtonian results is also presented. The applied non-Newtonian behavior of blood is based on measured dynamic viscosity. In the foreground of discussion are the flow characteristics in the carotid sinus. The investigation shows complex flow patterns especially in the carotid sinus where flow separation occurs at the outer wall throughout the systolic deceleration phase. The changing sign of the velocity near the outer sinus wall results in oscillating shear stress during the pulse cycle. At the outer wall of the sinus at maximum diameter level the shear stress ranges from -1.92 N/m2 to 1.22 N/m2 with a time-averaged value of 0.04 N/m2. At the inner wall of the sinus at maximum diameter level the shear stress range is from 1.16 N/m2 to 4.18 N/m2 with a mean of 1.97 N/m2. The comparison of non-Newtonian and Newtonian results indicates unchanged flow phenomena and rather minor differences in the basic flow characteristics.
利用三维几何模型对人体颈动脉分叉处的流动现象和壁面剪应力进行了数值分析。本研究的主要目的是详细讨论脉搏周期内的非牛顿流速和壁面剪应力。还给出了非牛顿和牛顿结果的比较。所应用的血液非牛顿行为基于测量的动态粘度。讨论的重点是颈动脉窦内的流动特性。研究表明，流动模式复杂，特别是在颈动脉窦内，在整个收缩期减速阶段，外壁会出现流动分离。窦外壁附近速度符号的变化导致脉搏周期内剪应力振荡。在窦最大直径水平的外壁处，剪应力范围为-1.92 N/m²至1.22 N/m²，时间平均值为0.04 N/m²。在窦最大直径水平的内壁处，剪应力范围为1.16 N/m²至4.18 N/m²，平均值为1.97 N/m²。非牛顿和牛顿结果的比较表明，流动现象不变，基本流动特性的差异较小。
