低频超声空化场中柱状泡群内气泡的声响应

发布时间：2018-01-19 14:45

本文关键词： 空化场空化气泡耦合振动声响应　出处：《物理学报》2016年14期 　论文类型：期刊论文

【摘要】：本文在气泡群振动模型的基础上,考虑气泡间耦合振动的影响,得到了均匀柱状泡群内振动气泡的动力学方程,以此为基础分析了低频超声空化场中柱形气泡聚集区内气泡的非线性声响应特征.气泡间的耦合振动增加了系统对每个气泡的约束,降低了气泡的自然频率,增强了气泡的非线性声响应.随着气泡数密度的增加,气泡的自然共振频率降低,受迫振动气泡受到的抑制增强.数值分析结果表明:1)驱动声波频率越低,气泡的初始半径越小,气泡数密度变化对气泡最大半径变化幅度的影响越大;2)气泡振动幅值响应存在不稳定区,不稳定区域分布与气泡初始半径、驱动声波压力幅值、驱动声波频率等因素有关.在低频超声波作用下,对初始半径处在1—10μm之间的空化气泡而言,气泡初始半径越小,气泡最大半径不稳定区分布范围越大,表明小气泡具有更强的非线性特征.因此,气泡初始半径越小,声环境变化对空化泡声响应稳定性影响越显著.
[Abstract]:On the basis of the vibration model of bubble group and considering the effect of coupling vibration between bubbles, the dynamic equation of vibration bubble in uniform cylindrical bubble group is obtained in this paper. On this basis, the nonlinear acoustic response of bubbles in the cylindrical bubble accumulation area in the low-frequency ultrasonic cavitation field is analyzed. The coupling vibration between bubbles increases the constraint of each bubble and reduces the natural frequency of the bubble. With the increase of bubble number density, the natural resonance frequency of the bubble decreases, and the suppression of forced vibration bubble is enhanced. The numerical results show that the lower the acoustic frequency is driven by 1). The smaller the initial radius of the bubble, the greater the influence of the number density of the bubble on the maximum radius of the bubble. 2) the amplitude response of bubble vibration has an unstable region. The distribution of the unstable region is related to the initial radius of the bubble, the amplitude of driving acoustic pressure and the frequency of driving acoustic wave, etc. Under the action of low-frequency ultrasonic wave. For cavitation bubbles whose initial radius is between 1-10 渭 m, the smaller the initial radius, the larger the distribution range of the unstable region of the maximum radius of the bubble, which indicates that the small bubble has stronger nonlinear characteristics. The smaller the initial radius of the bubble is, the more significant the change of sound environment has on the stability of cavitation bubble acoustic response.
【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(批准号:11204168,11474191) 中央高校基本科研业务费(批准号:Gk201603102)资助的课题~~
【分类号】：O35
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