Instabilities of convection rolls in a fluid of moderate Prandtl number
Instabilities of convection rolls in a fluid of moderate Prandtl number
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中等普朗特数流体中对流辊的不稳定性
DOI：
10.1017/s002211207900015x
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发表时间：
1979
影响因子：
3.7
通讯作者：
R. Clever
中科院分区：
文献类型：
--
作者：
F. Busse;R. Clever
本文研究了普朗特数小于等于7时水平流体层中二维对流辊的不稳定性。从理论和实验上描述了两种新的不稳定性机制。当瑞利数较高时，节结不稳定性导致向辐条型对流的转变，而扭曲的曲张不稳定性则导致对流辊向更大的水平波长的转变。这两个不稳定性都在小普朗特数和大普朗特数的范围内消失。虽然实验方法不能很好地实现理论中假定的无限导电边界，但观察到的结果在所有定性方面都与理论预测一致。
The instabilities of two-dimensional convection rolls in a horizontal fluid layer heated from below are investigated in the case when the Prandtl number is seven or lower. Two new mechanisms of instability are described theoretically as well as experimentally. The knot instability causes the transition to spoke-pattern convection at higher Rayleigh numbers while the skewed varicose instability accomplishes a change to larger horizontal wavelengths of the convection rolls. Both instabilities disappear in the limits of small and large Prandtl number. Although the experimental methods fail in realizing closely the infinitely conducting boundaries assumed in the theory, the observations agree in all qualitative aspects with the theoretical predictions.