STABILITY OF THE LAMINAR-FLOW IN A RECTANGULAR DUCT
STABILITY OF THE LAMINAR-FLOW IN A RECTANGULAR DUCT
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DOI：
10.1017/s002211209000204x
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发表时间：
1990-03-01
影响因子：
3.7
通讯作者：
YOSHIMURA, T
中科院分区：
文献类型：
--
作者：
TATSUMI, T;YOSHIMURA, T
通过将主流和扰动流场展开为勒让德多项式级数，求解矩阵方程的特征值问题，数值研究了任意长宽比矩形管道中层流的稳定性。流动的稳定性取决于管道的长宽比和扰动的模式。该流动对四种可能的不同宇称模式中的两种是不稳定的，对另外两种是稳定的。对于最不稳定的模式，流动是稳定的或不稳定的根据的纵横比是低于或高于一个临界值3.2分别，和临界雷诺数单调减少，随着增加的纵横比向已知的值5772的平面Poillille流。扰动的流场表明，沿速度等于扰动相速度的临界层存在沿着强涡层。
The stability of the laminar flow in a rectangular duct of an arbitrary aspect ratio is investigated numerically by expanding the flow fields of both the main flow and the disturbance into series of Legendre polynomials and solving the eigenvalue problem of the resulting matrix equation. The stability of the flow is found to depend upon the aspect ratio of the duct and the mode of the disturbance. The flow is unstable to two of the four possible modes of different parity and stable to the other two. With respect to the most unstable mode, the flow is stable or unstable according as the aspect ratio is below or above a critical value of 3.2 respectively, and the critical Reynolds number decreases monotonically with increasing aspect ratio towards the known value of 5772 for plane Poiseuille flow. The flow field of the disturbance shows the existence of strong vortex layers along the critical layer at which the velocity equals the phase velocity of the disturbance.