Local instability of a rotating flow driven by precession of arbitrary frequency
Local instability of a rotating flow driven by precession of arbitrary frequency
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DOI：
10.1088/0169-5983/43/5/055502
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发表时间：
2010-03
影响因子：
1.5
通讯作者：
Me Me Naing-Me;Y. Fukumoto
中科院分区：
文献类型：
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作者：
Me Me Naing-Me;Y. Fukumoto
我们重新审视具有圆形流线的旋转流的局部稳定性，对三维扰动，其旋转轴围绕垂直于自身的轴进行恒定的岁差运动。在旋转框架中，基本流是由Kerswell （1993 Geophys）构造的无界域中的坐标线性稳态速度场。12,54。Fluid Dyn. 72 107-44)，并承认使用Wentzel-Kramers-Brillouin （WKB）方法。对于较小的岁差频率，我们恢复了Kerswell的结果。在轴向波数在零附近振荡的大频率处，发现了一种新的不稳定性；扰动幅值的显著增长只发生在轴向波数消失前后的很短时间间隔内。在无限进动频率的极限下，增长率对表征波矢量倾斜角的参数表现出奇异性。
We revisit the local stability, to three-dimensional disturbances, of rotating flows with circular streamlines, whose rotation axis executes constant precessional motion about an axis perpendicular to itself. In the rotating frame, the basic flow is steady velocity field linear in coordinates in an unbounded domain constructed by Kerswell (1993 Geophys. Astrophys. Fluid Dyn. 72 107–44), and admits the use of the Wentzel–Kramers–Brillouin (WKB) method. For a small precession frequency, we recover Kerswell's result. A novel instability is found at a large frequency for which the axial wavenumber executes an oscillation around zero; significant growth of the disturbance amplitude occurs in a very short time interval only around the time when the axial wavenumber vanishes. In the limit of infinite precession frequency, the growth rate exhibits singular behavior with respect to a parameter characterizing the tilting angle of the wave vector.