A theoretical model of a liquid film flow in the presence of surface acoustic waves (SAWs) is established by involving the effects of an insoluble surfactant and evaporation on the spreading process of the partially wetting thin liquid film. A numerical simulation is performed to investigate the liquid film spreading dominated by the SAWs-induced drift of mass and the capillary stress. The simulated results show that SAWs drive liquid films to spread and move, and surfactants promote the further spreading and movement of liquid films, while liquid evaporation suppresses the spreading and movement. The inhibiting contribution of liquid evaporation to the liquid film dynamics is greater than the promoting contribution of the surfactant in this simulation. The mass loss of the liquid film caused by evaporation leads the spreading range to gradually retract. In addition, the spreading range has a positive correlation with the coefficient between the disjoining pressure and surfactant concentration and has a negative correlation with the Marangoni number. The spreading stability of liquid films is strengthened by the surfactant effect, while it is weakened by the evaporation effect.

中文翻译：

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表面活性剂和蒸发对声表面波存在下液体薄膜扩散的影响

通过涉及不溶性表面活性剂和蒸发对部分润湿的薄膜的扩散过程的影响，建立了在存在表面声波（SAW）的情况下液膜流动的理论模型。进行了数值模拟，以研究由声表面波引起的质量漂移和毛细应力主导的液膜扩散。模拟结果表明，声表面波驱动液膜扩散和运动，表面活性剂促进液膜进一步扩散和运动，而液体蒸发抑制液膜的扩散和运动。在此模拟中，液体蒸发对液膜动力学的抑制作用大于表面活性剂的促进作用。由蒸发引起的液膜质量损失导致扩展范围逐渐收缩。另外，扩展范围与分离压力和表面活性剂浓度之间的系数成正相关，而与马兰哥尼数成负相关。通过表面活性剂作用增强了液膜的铺展稳定性，而通过蒸发作用减弱了液膜的铺展稳定性。