两相流相界面迁移的数值模拟

该文采用VOF法追踪了重力流液液和气液相界面的迁移，发现VOF法可很好地追踪强非线性、大形变的相界面随时间的变化。重点讨论了不同相密度比、黏性比条件下，液液相界面和气液相界面的运动形式，验证了液液相界面主要受Kelvin-Helmholtz不稳定性控制。结果显示：液相密度比越大，液液相界面随时间变化越快，气液交界面不再保持水平位置，而以摆动的形式存在；在黏性比小于5时，黏性比不太影响液液相界面随时间变化。

Numerical simulation of interfacial flows

The interface/free-surface of gravity current surge is tracked by VOF method in this paper. It is found that the movement of the interfaces is well determined even in the cases of strong nonlinearity and large distortion by VOF method. The time-dependent interfaces of liquid-liquid and gas-liquid are simulated under the conditions of different ratio of density and viscosity of liquid phases. The liquid-liquid interfacial Kelvin Helmholtz instability foreseen by theory has been appeared and it is found this instability mechanism determines the development of wave action of interface and even breakup the interface finally. When increasing the ratio of density of liquid phases, the movement of liquid-liquid interface is becoming rapidly. Meanwhile, the horizontal gas-liquid free surface is not hold and becomes swing. For the ratio of liquid viscosity less than 5, the movement of liquid-liquid interface is hardly influenced by the ratio of liquid viscosity.