Time-modulated convection with zero mean temperature gradient.
Time-modulated convection with zero mean temperature gradient.
复制标题
平均温度梯度为零的时间调制对流。
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
R. Kelly
中科院分区：
文献类型：
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作者：
A. Or;R. Kelly
本文数值研究了边界温度为反对称和非对称的情况下，在连续的无量纲频率ω范围内，从ω约为O（10（-1））到ω约为O（10（3）），具有零平均梯度的时间调制Rayleigh-Bénard对流的开始。对于小于1的Ω，在两种情况下Pr=7的中性曲线在同步和次谐波响应之间交替，随着Ω变小，间隔越来越短。在大ω时，临界波数k（c）渐近于ω（1/2），临界瑞利数R（c）渐近于ω（3/2），在这两种情况下都是通过分谐波响应。与Niemela和Donnelly [Phys. Rev. Lett. 57，583（1986）]显示了相当合理的一致性。
We study numerically the onset of temporally modulated Rayleigh-Bénard convection with zero mean gradient for cases of antisymmetric and asymmetric boundary temperatures over a continuous range of nondimensional frequencies omega, from omega approximately O(10(-1)) to omega approximately O(10(3)). For omega below 1, the neutral curves for Pr=7 in both cases alternate between synchronous and subharmonic responses, with increasingly shorter intervals as omega becomes small. At large omega, the critical wave number k(c) asymptotes to omega(1/2) and the critical Rayleigh number R(c) asymptotes to omega(3/2), via a subharmonic response in both cases. A comparison with the experimental results of Niemela and Donnelly [Phys. Rev. Lett. 57, 583 (1986)] shows fairly reasonable agreement.