脉动流条件下动脉狭窄血管内脂质浓度极化现象的计算机数值模拟  

Computational simulation of LDL concentration polarization inarterial stenoses under pusatile flow conditions

作　　者：邓小燕[1] 刘柳军[1] 王贵学[1] 

机构地区：[1]重庆大学生物力学与组织工程教育部重点实验室

出　　处：《计算力学学报》2005年第1期25-31,共7页Chinese Journal of Computational Mechanics

基　　金：国家自然科学基金(10172027);国家教育部重点实验室资助项目.

摘　　要：在脉动流条件下,用计算机数值模拟的方法对低密度脂蛋白(LDL)在动脉狭窄血管段内的质量传输进行了研究。计算结果表明,无论是在定常流还是在脉动流条件下,LDL都将聚积于血管狭窄处峰口附近的流动分离点,LDL壁面浓度在此处最高。在脉动流条件下,LDL在血流受扰动区的聚积高于定常流的值;而且,流动分离点处LDL壁面浓度峰值覆盖的区域也宽于定常流。本文所揭示出的LDL在血管狭窄处的质量传输现象可能在动脉粥样硬化的局部性和动脉狭窄的形成中起着很重要的作用。It has been suspected that the concentration of atherogenic lipids at the luminal surface may vary according to its location in the arterial tree because of regional difference in wall shear rate, blood pressure, and vascular permeability. To substantiate the hypothesis of 'flow-dependent luminal surface lipid concentration' being involved in the localization of atherosclerosis, the transport of low-density lipoproteins (LDL) from flowing blood to the arterial wall in regions of disturbed blood flow distal to arterial stenoses was simulated numerically under both steady-state and pulsatile flow conditions. The analysis predicted that due to the presence of a filtration flow, LDL accumulated at the blood/arterial wall interface, with the highest concentration occurring at the flow separation point situated right distal to the summit of the stenosis constriction. The calculation showed that LDL accumulation in the disturbed flow region was somewhat higher under pulsatile flow than that under the steady-state flow. In addition, the highly concentrated LDL fluid layer in the vicinity of the flow separation point covered a larger area under pulsatile flow than under corresponding steady-state flow. It is therefore believed that the atherogenic lipid transport phenomena revealed in the study should be playing a significant role in atherogenesis in the human circulatory system.

关 键 词：质量传输 浓度极化 壁面剪切率 动脉粥样硬化 

分 类 号：O35[理学—流体力学]