Noise from Ventilated Supercavities and its Utility for Inferring Cavity Dynamics

Ventilated supercavities are shown to be monopole noise sources over a wide range of frequencies. As such, the radiated noise may have utility for providing insight into cavity characteristics, such as the entrainment rate of gas, cavity closure regime, and cavity stability. Lower frequency waves on the cavity interface define its shape and closure regime. When high amplitude, monotonic waves are present on the interface, corresponding high amplitude tones are present in the radiated noise. High frequency interface waves, associated with interface roughness, give rise to higher frequency broadband noise. Increased roughness increases the shear entrainment rate and ventilation requirements.