Effect of stretching on interfacial stability
Effect of stretching on interfacial stability
复制标题
拉伸对界面稳定性的影响
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
M. Blyth
中科院分区：
文献类型：
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作者：
C. Pozrikidis;M. Blyth
摘要：本文讨论了拉伸对两种不同粘度和密度流体之间水平界面稳定性的影响。局部拉伸流的作用是减小扰动的振幅，增加周期波的波长，从而改变扰动的瞬时增长率。Stokes流的线性稳定性分析表明，在两个半无限流体的水平交界面上存在正交驻点流动时，界面拉伸不能抑制不稳定分层流体的Rayleigh-Taylor不稳定性。相反，拉伸能够抑制放置在水平表面上的平坦膜的表面上的周期波的生长。Stokes流的边界积分方法的基础上的数值模拟证实，当拉伸流足够强时，膜表面上的局部扰动被抑制。
Summary.The effect of stretching on the stability of a horizontal interface between two fluids with different viscosities and densities is discussed. A local elongational flow acts to reduce the amplitude of perturbations and increase the wavelength of periodic waves, and thereby alter the instantaneous growth rate of disturbances. Linear stability analysis for Stokes flow reveals that, in the case of a horizontal interface between two semi-infinite fluids subjected to orthogonal stagnation-point flow, interfacial stretching is not able to suppress the Rayleigh-Taylor instability of unstably stratified fluids. In contrast, stretching is able to suppress the growth of periodic waves on the surface of a flat film resting on a horizontal surface. Numerical simulations based on the boundary-integral method for Stokes flow confirm that localized perturbations on the film surface are suppressed when the elongational flow is sufficiently strong.