超声声场中气泡的锥状聚集现象

Cone-like cavitation bubble formation in ultrasonic field

从非线性KZK(khokhlov-zabolotskaya-kuznetsov)方程出发,利用分离变量法,得到了换能器的声场分布表达式和声场分布图.结果表明,当轴向距离大于瑞利距离时,声压随距离增加逐渐减小到某一极限值,近似为平面波.声场中气泡锥状聚集主要发生区域是声压较大且呈现梯度的区域,气泡脉动影响声场分布,气泡间的Bjerknes力作用对气泡在高声压区的分布有调节作用,从而可引起声场出现锥状气泡结构现象.

Based on the nonlinear KZK （khokhlov-zabolotskaya-kuznetsov）equation, the expression and distribution of sound field are obtained. When the axis distance is beyond the Raileigh distance, the sound pressure will minimize to a certain limit value, which shows the sound field is a plane wave in that range. The CBS （Cone-like bubble structure） occurs in the area where the pressure is higher and the grads of pressure is not zero, The bubbles＇ radial vibration has an effect on the distribution of sound field. The mutual Bjerknes forces between bubbles adjust the distribution of bubbles, which causes CBS.