Univ Lyon, Université Claude Bernard Lyon 1, Centre Léon Bérard, INSERM, UMR 1032, LabTAU, F-69003, Lyon, France.
Univ Lyon, École Centrale de Lyon, INSA de Lyon, CNRS, LMFA UMR 5509, F-69134 Écully, France.
Phys Rev E. 2017 Dec;96(6-1):063104. doi: 10.1103/PhysRevE.96.063104. Epub 2017 Dec 5.
Time-resolved dynamics of nonspherical oscillations of micrometer-sized bubbles are captured and analyzed using high-speed imaging. The axisymmetry of the bubble shape is ensured with certainty for the first time from the recordings of two synchronous high-speed cameras located at 90^{∘}. The temporal dynamics of finite-amplitude nonspherical oscillations are then analyzed for various acoustic pressures above the instability threshold. The experimental results are compared with recent theories accounting for nonlinearities and mode coupling, highlighting particular effects inherent to these mechanisms (saturation of the instability, triggering of nonparametric shape modes). Finally, the amplitude of the nonspherical oscillations is given as function of the driving pressure both for quadrupolar and octupolar bubbles.
使用高速成像技术捕捉和分析了微尺度气泡的非球形振动的时间分辨动力学。通过位于 90 度的两个同步高速摄像机的记录，首次确定了气泡形状的轴对称性。然后，针对高于不稳定性阈值的各种声压，分析了有限振幅非球形振动的时间动力学。将实验结果与考虑非线性和模式耦合的最新理论进行了比较，突出了这些机制固有的特殊效应（不稳定性的饱和，非参数形状模式的触发）。最后，给出了四极和八极气泡的非球形振动幅度作为驱动压力的函数。
