粗糙弯曲动脉壁面剪应力分布的摩擦学效应

Some Biotribological Effects Caused by Shear Stress Distribution on Rough Luminal Wall of Curved Artery

文章以主动脉中复杂部位——弯曲血管作为分析对象,考虑人体心脏搏动作用和血管壁面与血液流动的相互影响,采用计算流体动力学技术,对因低密度脂蛋白等粒子沉积形成的粗糙斑块对血管中壁面剪应力分布的影响进行了研究,力图阐明特定条件下的血液流动的摩擦学效应。研究工作表明,弯曲血管中主动脉弓与降主动脉交界处内侧出现的粗糙斑块,其高度、间距以及分布情况的变化,对血管壁面剪应力的分布和数值都有很大的影响,粗糙斑块的存在及结构状态的变化造成的血管壁面剪应力的"振荡波动"影响和数值的突增,将对动脉血管病变的萌生和发展有很大影响,这一过程中表现出来的摩擦学效应应引起注意。

The influence of atherosclerotic plaques on blood flow and on wall mechanical properties in blood vessels plays a key role in atherogenesis.Section 1 of the full paper presents a model of a curved artery that contains rough plaques;this model is largely based on what is already known in the open literature but is modified by us in minor aspects;it fully considers the fluid-structure interaction and is used to investigate the change in wall shear stress under physiologically pulsatile flow condition in order to explain some biotribological effects on blood flow.The calculation results,given in Figs.2,3,4 and 5,and their analysis show preliminarily that the height,interval and distribution of the rough plaques existing in cardiovascular lumen all have great effects on the peak value and distribution of the wall shear stress in a local artery and cause the drastic oscillation of the wall shear stress.These effects may contribute to further development and new formation of plaques and finally lead to arterial stenosis.