The instability of a straight vortex filament in a strain field
The instability of a straight vortex filament in a strain field
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DOI：
10.1098/rspa.1975.0183
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发表时间：
1975-11
期刊：
影响因子：
--
通讯作者：
D. W. Moore;P. Saffman
中科院分区：
文献类型：
--
作者：
D. W. Moore;P. Saffman
有限截面的无限长直涡在弱无旋平面应变作用下发生变形。变形涡示出，在轴向流的情况下，是不稳定的扰动，其轴向波长位于一个窄带，其宽度是成比例的所施加的应变。该带的中心在螺旋波的波长上，螺旋波不在无应变的圆形涡旋上传播。从而支持了Widnall，布利斯& Tsai（1974）最近提出的不稳定机制。然而，这一论点取决于螺旋波的镜像，螺旋波也可能是对无应变涡的非传播扰动。
A straight infinite vortex of finite cross section is deformed by the action of weak irrotational plane strain. The deformed vortex is shown, in the absence of axial flow, to be unstable to disturbances whose axial wavelengths lie in a narrow band, whose width is proportional to the imposed strain. The band is centred on the wavelength of the helical wave which does not propagate on the unstrained circular vortex. Thus support is given to the instability mechanism proposed recently by Widnall, Bliss & Tsai (1974). The argument depends, however, on the mirror image of the helical wave also being a possible non-propagating disturbance on the unstrained vortex.