蒸发两层流系统的对流不稳定性分析

关于蒸发液层的Rayleigh-Marangoni-Benard不稳定性的研究中,早期文献中普遍采用的是单层流模型。近年来,一些学者采用两层流模型对蒸发稳定性进行了理论分析,有的文献中没有考虑蒸发率与饱和蒸汽压的耦合关系,所以得到的结果不能完全反应蒸发对系统稳定性的影响。本文建立了一种新的两层流模型,考虑了界面变形对系统稳定性的影响。采用线性稳定性方法对带有蒸发界面的两层流的Rayleigh-Marangoni-Benard对流不稳定性进行了分析,得到了临界 Marangoni数与波数的关系,重点讨论了蒸发系数以及重力对汽液两层流系统的不稳定性的影响。

ANALYSIS ON THE CONVECTIVE INSTABILITY OF TWO LAYER EVAPORATION SYSTEM

One-sided model is proposed in previous works about the research on the Rayleigh-Marangoni-Benard instabilities of the evaporating liquid layer. Recently, some investigators proposed two-sided model to analyze the instabilities of evaporating vapor-liquid system, but the relation between evaporation flux and saturate pressure has not been taken into account, hence these results can not reflect the influence of evaporation on the instability of the system. In the present paper, a new two-sided model is proposed and the interface deflection is taken into account. Rayleigh-Marangoni-Benard instabilities of the two layer system with an evaporating interface are discussed by Linear instability analyses method. The curves of critical Marangoni number versus wavenumber are obtained and the influence of evaporating coefficient and gravity on the instabilities of the system were discussed.