泡群内气泡振动特性分析

发布时间：2018-07-31 19:36

【摘要】：本文从均匀球状泡群内气泡非线性振动方程出发分析了驱动声压幅值、声波频率和液体环境对空化气泡振动特性的影响.数值分析结果表明:超声波驱动下的非线性振动气泡存在不稳定响应区,不稳定响应区主要分布在声波频率小于5 0 kHz的低频区和平衡半径小于1 0μm的微泡尺寸范围;平衡半径为3μm左右的空化微泡有较强的声响应能力和不稳定性,在特定的液体和声环境中,极易受到扰动生长为平衡半径更大的气泡;驱动声波频率一定的情况下,随着驱动声波压力的增加,气泡的非线性共振频率降低,声场中气泡的共振尺寸减小;平衡半径大的气泡空化阈值低,更容易引起空化效应.液体内溶解气体浓度影响空化进程以及空化声压阈值,溶解气体浓度越低空化阈值越高.
[Abstract]:In this paper, the effects of the amplitude of driving sound pressure, the frequency of acoustic waves and the liquid environment on the vibration characteristics of cavitation bubbles are analyzed based on the nonlinear vibration equation of bubbles in a uniform spherical bubble group. The numerical results show that there is an unstable response region in the nonlinear vibration bubble driven by ultrasonic wave. The unsteady response region is mainly distributed in the low frequency region with acoustic frequency less than 50 kHz and the microbubble size with a balance radius of less than 10 渭 m. The cavitation microbubbles with a balance radius of about 3 渭 m have strong acoustic response ability and instability. In a specific liquid and acoustic environment, they are easily disturbed to grow into bubbles with a larger equilibrium radius, and the sound waves are driven by a constant frequency of sound waves. With the increase of the pressure of driving sound wave, the nonlinear resonance frequency of the bubble decreases, the resonance size of the bubble decreases in the sound field, and the cavitation threshold of the bubble with large equilibrium radius is low, which is more likely to cause cavitation effect. The concentration of dissolved gas in liquid affects the cavitation process and the threshold of cavitation sound pressure, and the lower the concentration of dissolved gas is, the higher the cavitation threshold is.
【作者单位】：陕西师范大学超声学重点实验室;
【基金】：国家自然科学基金(编号:11204168,11474191) 中央高校基本科研业务费专项资金(编号:Gk201603102)资助项目
【分类号】：O35

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