热毛细效应对细丝薄膜流动不稳定性的影响

Effect of Thermocapillary on the Absolute and Convective Stabilities of a Thin Flim Flowing down a Fibre

根据重力与热毛细力耦合作用薄膜在细丝上的流动情况,采用长波近似推导了界面的演化方程.通过色散关系分析热毛细作用对Rayleigh-Plateau稳定性的影响;通过时空模式的稳定性分析,研究了系统的绝对对流不稳定性特性;通过直接数值模拟,研究了薄膜破裂和绝对对流稳定性的关系.

The dynamics of a viscous film flowing down a vertical fibre under the action of gravity and the thermocapillary is analyzed theoretically.This exterior coating flow is driven by a RayleighPlateau mechanism modified by the presence of gravity as well as the variation of surface tension induced by temperature gradient along the interface.A temporal-spacial stability analysis is performed to investigate the influence of the thermocapillarity on the convective/absolute instability（CI/AI） of axisymmetric disturbances.The results show that the thermocapillary plays an important role in determining the CI/AI characteristics in different flow regimes.