GPU accelerated numerical investigation of the spherical stability of an acoustic cavitation bubble excited by dual-frequency

The spherical stability of an acoustic cavitation bubble under dual-frequency excitation is investigated numerically. The radial dynamics is described by the Keller-Miksis equation, which is a second-order ordinary differential equation. The surface dynamics is modelled by a set of linear ordinary differential equation according to Hao and Prosperetti (1999), which takes into account the effect of vorticity by boundary layer approximation. Due to the large amount of investigated parameter combinations, the numerical computations were carried out on graphics processing units. The results showed that for bubble size between RE = 2 mu m and 4 mu m, the combination of a low and a high frequency, and the combination of two close but not equal frequencies are important to prevent the bubble losing its shape stability, while reaching the chemical threshold (Rmax/RE = 3) (Kalm ' ar et al., 2020). The phase shift between harmonic components of dual-frequency excitation has no effect on the shape stability.

Automated summary

The study numerically investigated the spherical stability of an acoustic cavitation bubble under dual-frequency excitation. The results showed that the combination of low and high frequencies, as well as two close but not equal frequencies, is important for maintaining the shape stability of the bubble when the diameter is between 2 μm and 4 μm.