The effect of Prandtl number on the evolution and stability of Kelvin-Helmholtz billows
The effect of Prandtl number on the evolution and stability of Kelvin-Helmholtz billows
复制标题
普朗特数对开尔文-亥姆霍兹巨浪演化和稳定性的影响
DOI：
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发表时间：
1985
期刊：
影响因子：
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通讯作者：
W. Peltier
中科院分区：
文献类型：
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作者：
G. Klaassen;W. Peltier
摘要 采用二维数值模型计算了不同普朗特数流体中开尔文-亥姆霍兹波涛的非线性演化。我们对这些非线性波的能量收支进行了详细分析，并研究了波能循环对流体普朗特数的依赖性。然后，我们测试了这些与时间相关的二维波态对于全三维无穷小扰动的稳定性，并发现它们对于由非线性波核心中翻转流体的对流不稳定性触发的纵向扰动最不稳定。我们发现，增加普朗特数往往会使非线性波相对于这些纵向扰动变得不稳定。
Abstract A two-dimensional numerical model is employed to calculate the nonlinear evolution of Kelvin-Helmholtz billows in fluids with various Prandtl numbers. We present a detailed analysis of the energy budget of these nonlinear waves and investigate the dependence of the wave energy cycle on the Prandtl number of the fluid. We then test these time dependent two-dimensional wave states for stability against fully three- dimensional infinitesimal perturbations, and find that they are most unstable against longitudinal disturbances which are triggered by convective instability of the overturning fluid in the core of the nonlinear wave. We find that increasing the Prandtl number tends to destabilize the nonlinear wave with respect to these longitudinal disturbances.