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目的经典的单相牛顿血液流动模型忽略了红细胞与血浆之间的相互作用以及血液剪切变稀性质。为解决这些问题,采用多相的非牛顿模型研究冠状动脉模型的血流动力学参数。方法把血液考虑为血浆和红细胞的混合体,并用螺旋弯曲血管模型模拟冠状动脉,分析冠状动脉内红细胞的运动以及红细胞体积分数的分布情况,并与单相非牛顿血液模型的模拟结果进行对比。结果单相和多相血液模型模拟下的截面壁面剪切力平均值差别不明显,但是在两相流模拟中,螺旋弯曲管下底壁面处存在明显的红细胞聚集现象,同时还分布着较低的壁面剪切力。结论引用多相流数值模拟得到了螺旋弯曲管中的血流动力学参数,同时发现红细胞在螺旋弯曲管下底面处聚集的现象,这很容易诱发血栓形成,与临床上所观察到的粥样硬化斑块经常出现在冠状动脉弯曲内侧是相符合的,可进一步说明动脉粥样硬化病变的发生机制。
Objective The classic single-phase Newtonian blood flow model ignores the interaction between red blood cells and plasma as well as the shear thinning properties of blood. In order to solve these problems, the heterogeneous non-Newtonian model was used to study the hemodynamic parameters of coronary artery model. Methods Blood was considered as a mixture of plasma and erythrocytes, and the coronary arteries were simulated by helical tortuous vascular model. The distribution of erythrocyte motility and erythrocyte volume fraction in coronary arteries were analyzed. The results were compared with those obtained from single-phase non-Newtonian blood model. Results There was no obvious difference between the average wall shear forces under the single-phase and multi-phase blood model simulations. However, in the two-phase flow simulation, there was obvious aggregation of erythrocytes at the bottom wall of the spiral bends, Wall shear force. Conclusions The multi-phase flow numerical simulation is used to obtain the hemodynamic parameters of the helical bending tube. At the same time, it is found that the erythrocytes accumulate on the bottom surface of the helical bending tube, which can easily induce thrombosis. Compared with the clinically observed atherosclerosis Sclerosis plaques often appear in the medial curve of the coronary artery is consistent with, and can further explain the pathogenesis of atherosclerotic lesions.