  The present work aims to study the cavitating turbulent flow of a full-scale
marine propeller and explore the physical mechanism underpinning the underwater
radiated noise. We employ the standard dynamic large eddy simulation for the
turbulent wake flow and the Schnerr-Sauer cavitation model, while the
Ffowcs-Williams-Hawkings acoustic analogy is considered for the hydroacoustic
modeling. For the current investigation, we consider a well-known Potsdam
Propeller Test Case to analyze the turbulent cavitating flow and the associated
hydroacoustic emissions. To begin, the modeling framework is validated using
the available experimental data, and distinctive double-helical tip vortex
cavitation and its qualitative patterns along the vortex trajectory are
captured. In comparison to the non-cavitating condition, the pressure
distribution on the propeller surface is more disordered for the cavitating
condition, which is further reflected by a relatively stronger power of both
low-frequency tonal peaks and high-frequency broadband components in the
spectrum of thrust generation. Specifically, the generation of cavitation leads
to the enhancement of the monopole noise source and the breakdown of cavitation
bubbles as well as vortex structures in the turbulent wake. Furthermore, the
tonal noise with the frequency corresponding to the harmonics of blade passing
frequency is also enhanced. Generally speaking, the generation of cavitation
structures enhances the hydroacoustics energy of URN at all orientations,
especially in the downstream direction with sound pressure level increasing up
to 20 dB.
