Modeling Gas Oscillations Following a Confined Underwater Release

The sudden, underwater rupture of a finite canister of air was studied by time-resolved pressure and interfacial geometry measurements. Two distinct dynamical regimes for the air remaining in the canister were identified: an inertial regime, in which the air oscillated with increasing frequency, and a capillary regime, in which emerging air bubbles pinched off from the air remaining in the canister. The temporal scales for these regimes were identified, and the inertial regime was shown to follow Rayleigh-Plesset dynamics with an empirically defined characteristic length scale associated with the air volume. The spectral dynamics of the two regimes were reproduced by modifying the Rayleigh-Plesset equation to include mass/energy losses, viscous damping, and a time-dependent capillary forcing.