摘要
以血液流动为背景,利用双参数摄动法研究了圆截面螺旋管内低频振荡流动,得到问题的二阶摄动解,分析了轴向速度、二次流、壁面剪应力在不同时刻的特点及随时间和Womersley数的变化情况· 研究表明:挠率对圆截面曲线管道内低频振荡流动的影响不可忽略,尤其是轴向压力梯度绝对值很小时,挠率将对二次流动结构起主要影响作用· 流函数的剧烈变化只发生在正、负数值发生转变的很小的时间段内。
A study on the unsteady low_frequency oscillatory flow in a helical circular pipe is carried out based upon the blood flow in vessels, using the method of bi_parameter perturbation. The second order perturbation results were obtained and the characteristics were analyzed at different time of the axial velocity, of the secondary flow, and of the wall shearing stress. Also done the analysis of above_mentioned variables that varied along with time and Womersley number. The results indicate that for a helical pipe, the torsion exerts the main influence on the distribution of secondary flow velocity, especially when the absolute value of axial press gradient is rather small. The severe variation of stream function takes place within a very short period, during which time the stream function develops from positive value to negative value and vice versa, while in most cases in a cycle, the variation is smooth. The wall shearing stress changes severely with theta too.
出处
《应用数学和力学》
EI
CSCD
北大核心
2003年第5期519-528,共10页
Applied Mathematics and Mechanics
基金
国家自然科学基金资助项目(10272096)
关键词
振荡流动
摄动法
螺旋管道
oscillatory flow
perturbation method
helical pipe
