Convective instability and transient growth in steady and pulsatile stenotic flows
Convective instability and transient growth in steady and pulsatile stenotic flows
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DOI：
10.1017/s0022112008001717
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发表时间：
2008-07-25
影响因子：
3.7
通讯作者：
Barkley, D.
中科院分区：
文献类型：
--
作者：
Blackburn, H. M.;Sherwin, S. J.;Barkley, D.
结果表明，对于具有轴对称75%闭塞狭窄的直管中的定常或长周期脉动流动，适当的初始扰动可以产生很大的瞬时能量增长。通过线性分析发现，对初始轴对称状态的全局最优扰动是在扩展剪切层中产生局部正弦对流不稳定的三维波包。在脉动流中，触发最大扰动的初始条件要么在狭窄处的分离剪切层处开始，要么平流到与收缩峰值流同相的分离剪切层。这份报纸的在线版本提供了电影。
We show that suitable initial disturbances to steady or long-period pulsatile flows in a straight tube with an axisymmetric 75%-occlusion stenosis can produce very large transient energy growths. The global optimal disturbances to an initially axisymmetric state found by linear analyses are three-dimensional wave packets that produce localized sinuous convective instability in extended shear layers. In pulsatile flow, initial conditions that trigger the largest disturbances are either initiated at, or advect to, the separating shear layer at the stenosis in phase with peak systolic flow. Movies are available with the online version of the paper.