超声激励薄液膜Faraday波形成机理

针对35 kHz超声激励薄液膜形成的Faraday波，采用实验和有限元仿真，对Faraday波的形成机理进行探究。建立超声激励下的两相流计算模型，采用计算流体力学（CFD）方法对Faraday波的形成过程进行有限元仿真，通过分析相图和流线图，探讨Faraday波的形成机理，得到Faraday波的振动频率约为超声激励频率的1/2。液体惯性的存在，导致超声激励与液体表面波存在不断变化的相位差，相位差变化周期约等于2个超声激励周期。通过35 kHz超声激励薄液膜实验，在薄液膜表面观察到排列整齐的Faraday波图案，通过测量Faraday波的波长，得出实验获得的Faraday波频率约为超声激励频率的1/2，与有限元仿真结果一致。 

Formation mechanism of Faraday wave on thin liquid film excited by ultrasonic vibration

Aimed at the Faraday wave formed by 35 kHz ultrasonic excitation on thin liquid film, the formation mechanism of Faraday wave was explored by experiments and finite element simulation. The two-phase flow calculation model under ultrasonic excitation was established. The finite element simulation of the formation process of Faraday wave was carried out by CFD method. The formation mechanism of Faraday wave was discussed by analyzing the phase diagram and streamline diagram. The vibration frequency of Faraday wave was about 1/2 of the drive frequency. The existence of liquid inertia resulted in a constantly varying phase difference between the ultrasonic excitation and the liquid surface wave, and the phase difference variation period was about two ultrasonic excitation periods. Through the 35 kHz ultrasonic excitation experiment on thin liquid film, a well-arranged Faraday wave array pattern was observed on the surface of the thin liquid film. By measuring the wavelength of the Faraday wave, it was deduced that the surface wave frequency obtained by the experiment was about 1/2 of the ultrasonic frequency, and consistent with the results of finite element simulation.