Mutations of steady cellular flows in the Taylor experiment
Mutations of steady cellular flows in the Taylor experiment
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泰勒实验中稳定细胞流的突变
DOI：
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发表时间：
1982
影响因子：
3.7
通讯作者：
T. Mullin
中科院分区：
文献类型：
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作者：
T. Mullin
用流动可视化的方法研究了同心圆柱间泰勒涡流动的各种稳态。实验主要集中在初级流的演变上，即由雷诺数R参数化的稳态连续体上，从小R开始，初级流是唯一可能的。对于任何特定的长径比Γ，初级流在较高的R下发展出明确的细胞模式，但随后也可能出现其他稳定的细胞流（次级模式）。所提出的观察结果表明，随着Γ在临界值上的变化，初级流的突变发生了变化：其r依赖的进化因此从一个细胞阵列切换到另一个更高r的细胞阵列。在四种情况中（4 - 6,6 - 8,8 - 10和10-12细胞），突变被证明涉及初级流位点的滞后和与次级模式的复杂相互作用。在第2节对仪器的描述之后，第3节将讨论用于观察通常很微妙的迟滞效应的实验方法。第4节的实验结果与先前在泰勒实验中所显示的抽象数学概念大体一致，但也发现了一些新的和令人惊奇的特征，如细胞对之间的耦合。
Aspects of the various steady states of Taylor-vortex flow between concentric cylinders have been investigated by means of flow visualization. The experiments have focused principally on the evolution of the primary flow, that is, on the continuum of steady states parametrized by the Reynolds number R, beginning at small R where the primary flow is the only one possible. For any particular aspect ratio Γ, the primary flow develops a well-defined pattern of cells at higher R, but then other steady cellular flows (secondary modes) are also possible. The observations presented demonstrate mutations of the primary flow as Γ is varied through critical values: its R-dependent evolution is thereby switched from one to another array of cells realized at higher R. In each of four cases (4–6, 6–8, 8–10 and 10–12 cells), the mutation is shown to involve hysteresis of the primary-flow locus and complicated interactions with secondary modes. Following a description of the apparatus in §2, a discussion of the experimental method used to observe the often delicate hysteresis effects is given in §3. The experimental results in §4 are in broad agreement with abstract mathematical ideas that have been previously shown to bear on the Taylor experiments, but several new and surprising features, such as the coupling between pairs of cells, have been uncovered.