声模态对超声破碎空化场的影响

以20 kHz浸入式超声破碎装置为研究对象，将声场分析与有限元方法相结合，分析了超声破碎料腔在不同声场条件下（液位高度、声源位置）的声模态特性，并对超声场内的空化分布和平均声能密度的变化规律进行探讨，最后应用声学测量方法和图像采集试验进行了验证。结果表明：超声空化的空间分布与料腔中声场的声模态特性相关；料腔半径一定，当液位达到料腔声场的谐振液位时，场内平均声能密度较高，空化效应显著增强，空间分布与场内声压分布一致。在谐振液位时，声源位置的布放对平均声能密度和空化增强影响显著。

Research on the effect of acoustic mode on ultrasonic broken cavitation field

The immersion ultrasonic crushing device under 20 kHz is investigated in this study. Combined the sound field analysis and the finite element method, we firstly examine the acoustic mode properties of ultrasonic crushing material cavity on different sound field conditions, i.e. the height of liquid level and the position of sound source, and then explore the distribution of ultrasonic cavitation field and the change laws on the average acoustic energy density. Finally, experiments with acoustic measurement methods and image acquisition are made to verify these explorations. Experimental results shows that the distribution of ultrasonic cavitation field is related to the acoustic modal properties of the sound field. With the value of material cavity radius fixed, when the liquid level reaches the resonant of material cavity at height, the average acoustic energy density in the field is higher and the cavitation effect is significantly enhanced, and the distribution of ultrasonic cavitation field is found similar to that of the material cavity sound field. In the resonance level, the position of the sound source has obvious effect on the average acoustic energy density and cavitation enhancement.