Three-dimensional oscillation of an acoustic microbubble between two rigid curved plates

Understanding the near boundary acoustic oscillation of microbubbles is critical for the effective design of ultrasonic biomedical devices and surface cleaning technologies. Accordingly, this study investigates the three-dimensional microbubble oscillation between two curved rigid plates experiencing a planar acoustic field using boundary integral method (BIM). The numerical model is validated via comparison with the nonlinear oscillation of the bubble governed by the modified Rayleigh-Plesset equation and with the axisymmetric model for an acoustic microbubble in infinite fluid domain. Then, the influence of the wave direction and horizontal standoff distance (h) on the bubble dynamics (including jet velocity, jet direction, centroid movement, total energy, and Kelvin impulse) were evaluated. It was concluded that the jet velocity, the maximum radius and the total energy of the bubble are not significantly influenced by the wave direction, while the jet direction and the high-pressure region depend strongly on it. More importantly, it was found that the jet velocity and the high-pressure region around the jet in acoustic bubble are drastically larger than their counterparts in the gas bubble.