摘要
目的:探究薄膜流体共振现象的内在机理。创新点:1.提出薄膜流体共振区的概念。2.提出共振现象与雷诺数的范围有关、而不是与某一特定的雷诺数有关的观点。方法:1.使用有限体积法对薄膜流进行数值模拟计算。2.为了验证模拟的准确性,运用粒子图像测速法进行实验测量。结论:1.薄膜流体共振可以使自由表面的振荡最大化。2.共振现象与雷诺数的范围有关,而不是与特定的雷诺数有关。3.在共振区域中,薄膜表面的振动增强,底部涡流被抑制,并且这些都有利于传热传质效率的提高。
The oscillation of gas–liquid interface is enhanced when film flows over a specific corrugation under certain flow conditions. The resonance phenomenon occurs when the free surface amplitude reaches its maximum. In this study, the resonance section is proposed for the first time in which the oscillation of the film surface is enhanced and bottom eddies are suppressed. The trend of the bottom eddies inspires the discovery of the resonance section. The dynamic characteristics of the resonance phenomenon were analyzed by simulations and experiments. The numerical simulations were performed with the open source software OpenFOAM, and the experiments were conducted by the particle image velocimetry(PIV) method. In the resonance section, the dynamic characteristics are different from the other sections: the upper and lower bounds of the resonance section correspond to the two inflection points of free surface amplitude, the variations in average liquid film thickness are slight, and the normal velocity intensity of the free surface is increased. Additionally, the enhancement of velocity intensity occurs within a region.
