蒸发或冷凝薄液膜的时域稳定性特征

Temporal stability characteristics of evaporating or condensing thin liquid film

基于Prandtl边界层理论和完整的边界条件,采用Collocation方法,推导出沿倾斜壁面下降的在蒸发、等温和冷凝状态下普遍适用的二维降膜表面波扰动时域稳定性方程。通过研究蒸发或冷凝薄液膜流动的稳定性特征曲线,包括中性稳定性曲线和最快速波的特征曲线,分析了蒸发、等温和冷凝等不同状态下热毛细力、雷诺数、流体物性和壁面倾角对稳定性的影响,并讨论了上述各因素在不同雷诺数下的相对作用。

The temporal stability equation of the two-dimensional waves of the evaporating or isothermal or condensing liquid films falling down an inclined wall is established for the film thickness with the collocation method based on the Pfandtl boundary layer theory and complete boundary conditions. By investigating the flow temporal characteristics curves, including the neutral stability curves and stability curves of the fastest wave, the effects on flow stability of evaporating, isothermal and condensing states, thermal capillarity, Reynolds number, fluid property and inclined angle are discussed and compared in different Reynolds numbers.