搜索

x
中国物理学会期刊

超声场中单气泡的平移和非球形振动

CSTR: 32037.14.aps.70.20210513

Translation and nonspherical oscillation of single bubble in ultrasound field

CSTR: 32037.14.aps.70.20210513
PDF
HTML
导出引用
  • 基于摄动理论和广义伯努利方程, 推导出单气泡在超声场中径向振动方程、平移方程和气泡形变方程. 数值计算这3个方程, 可以得到气泡半径、气泡中心的位移和气泡形变随时间的演化图. 计算结果表明: 当气泡初始半径和驱动声压不变时, 气泡中心初始平移速度增大, 气泡径向振动几乎不变, 但气泡中心位移和形变量增大, 气泡非球形振动愈加明显. 当初始平移速度比较小时, 气泡的R_0\text -p_\rm a相图中, 不稳定区域仅集中在高驱动声压区域. 随着气泡中心初始平移速度不断增大, 半径和驱动声压均较小的区域开始呈现不稳定性, 且整体不稳定空间范围逐渐增大. 另外, 气泡在声驻波场中不同位置呈现出不同的振动特征. 离波腹点越近的气泡, 其径向振动幅度越大, 但气泡的平移和形变量变化很小, R_0\text - p_\rm a相图中不稳定性区域平面分数之间的误差小于4%.

     

    Based on the perturbation theory and generalized Bernoulli equation, the equations describing the radius, translation and deformation of a single gas bubble in ultrasonic field are derived. The evolutions of the radius, displacement and deformation of the bubble with time can be obtained by numerically calculating these equations. The calculation results show that when the initial radius of the bubble and the driving pressure both keep constant, the displacement and shape variable of the bubble increase with the augment of the initial translational velocity of the bubble’s center, and the non-spherical vibration of the bubble becomes more intense. However, the radial vibration of the bubble almost remains unchanged. When the initial translation velocity of the bubble is relatively small, the unstable region is concentrated only in the region of high driving sound pressure in the R_0\text-p_\rm a phase diagram of the bubble. As the initial translational velocity increases, the region with small radius and driving sound pressure begins to show instability, and the overall unstable region gradually increases. In addition, a bubble presents different vibration characteristics at different positions in the acoustic standing wave field. The closer to the antinode of sound wave the bubble is, the greater the radial amplitude of the bubble’s vibration is. However, the variable of the translation and shape of the bubble are very small. The error between the plane fractions of the unstable region in the phase diagram of R_0\text- p_ \rm a is less than 4%.

     

    目录

    /

    返回文章
    返回