Effect of Thermocapillary on Absolute and Convective Instability of Film Flow of Self-Rewetting Fluid
Effect of Thermocapillary on Absolute and Convective Instability of Film Flow of Self-Rewetting Fluid
复制标题
DOI：
10.1007/s12217-019-09778-8
复制
发表时间：
2020-01
影响因子：
1.8
通讯作者：
Longgang Dong;Xuemei Li;Rong Liu
中科院分区：
文献类型：
--
作者：
Longgang Dong;Xuemei Li;Rong Liu
研究了重力作用下自再湿膜沿垂直纤维沿着下落的动力学问题。在长波近似下，建立了自再湿膜界面的演化方程。研究了热毛细作用（Marangoni效应）对表面张力与表面温度成二次函数的自再润湿流体的绝对/对流不稳定性（AI/CI）的影响。通过研究色散关系，研究了热毛细作用对瑞利-平台不稳定性的影响。自再湿流体的特性被认为是不同的Marangoni数（Ma）在不同的区域的绝对/对流不稳定性使用的时空稳定性分析。数值模拟的非线性演化在不同区域的绝对/对流不稳定。数值模拟的结果与时空稳定性分析吻合得很好。热毛细作用对绝对和对流不稳定性的影响取决于界面处的温度与对应于最小表面张力Θ0的温度之间的差。结果表明，随着Ma的增大，热毛细作用抑制了绝对不稳定性，增强了对流不稳定性;随着Ma的增大，热毛细作用增强了绝对不稳定性。
The dynamics of a self-rewetting film falling along a vertical fiber under the influence of gravity are considered. The evolution equation of the interface of the self-rewetting film is established in the framework of a long-wave approximation theory. The effect of thermocapillarity (Marangoni effect) on the absolute/convective instability (AI/CI) is investigated for self-rewetting fluids of which the surface tension is a quadratic function of the temperature at the surface. The effect of thermocapillarity on the Rayleigh-Plateau instability is investigated by examining the dispersion relation. The characteristics of self-rewetting fluids are considered for different Marangoni numbers (Ma) in different regions of absolute/convective instability using a spatio-temporal stability analysis. Numerical simulations of the nonlinear evolution in various regions of absolute/convective instability are also performed. The results of numerical simulations are in excellent agreement with the spatio-temporal stability analysis. The effect of thermocapillarity on absolute and convective instability depends on the difference between the temperature at the interface, and the temperature corresponding the minimum surface tensionΘ0. The results indicate that the thermocapillarity suppresses the absolute instability and enhances the convective instability asMaincreases when, and enhances the absolute instability asMaincreases when.