Characteristics of disturbances in the laminar–turbulent transition of spherical Couette flow. 1. Spiral Taylor–Görtler vortices and traveling waves for narrow gaps
Characteristics of disturbances in the laminar–turbulent transition of spherical Couette flow. 1. Spiral Taylor–Görtler vortices and traveling waves for narrow gaps
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DOI：
10.1063/1.1502661
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发表时间：
2002-09
影响因子：
4.6
通讯作者：
K. Nakabayashi;Yoichi Tsuchida;Zhiming Zheng
中科院分区：
文献类型：
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作者：
K. Nakabayashi;Yoichi Tsuchida;Zhiming Zheng
通过同步和流动可视化测量，研究了两个同心球之间仅内球旋转的球形库埃特流的层流-湍流转变中由扰动（涡流和波）引起的速度脉动的基本频率，这两个小比率（0.06和0.024）的间隙与内球半径的比值（0.06和0.024），其中螺旋泰勒-戈特勒（TG）涡旋和TG涡旋上的行波发挥着重要作用角色。随着两个间隙比的雷诺数Re增加，赤道处首先出现环形TG涡，但流动是稳定的。其次，螺旋 TG 涡流（基本频率 fSi）出现在环形涡流旁边，因此流动变得单周期。第三，除了这些螺旋TG涡之外，它们之间在不同纬度θ处还会产生新的螺旋TG涡，使得球环周围的螺旋TG涡对数相差θ。因此，螺旋的复数基频 fSi (i=1,2,…)...
The fundamental frequencies of velocity fluctuations caused by disturbances (vortices and waves) in the laminar–turbulent transition of spherical Couette flow between two concentric spheres with only the inner sphere rotating are investigated by simultaneous and flow-visualization measurements for two small ratios, 0.06 and 0.024, of the clearance to inner-sphere radius for which spiral Taylor–Gortler (TG) vortices and traveling waves on TG vortices play an important role. As the Reynolds number Re is increased for both clearance ratios, first toroidal TG vortices occur at the equator, but the flow is steady. Second, spiral TG vortices (fundamental frequency fSi) occur next to the toroidal ones, so that the flow becomes singly periodic. Third, in addition to these spiral TG vortices, new spiral TG vortices occur between them at the different colatitude θ, so that the pair number of spiral TG vortices around the spherical annulus differs by θ. Therefore, plural fundamental frequencies fSi (i=1,2,…) of spir...