Wall-modeled large-eddy simulation of noise generated by turbulence around an appended axisymmetric body of revolution

The directivity of the noise generated by turbulent flows around an underwater vehicle (the fully appended SUBOFF body) is investigated numerically, where the turbulent flows are simulated by using the large eddy simulation (LES) with a non-equilibrium wall model and the noise is calculated by using the Ffowcs Williams and Hawking formulation. The wall-modeled LES reproduces the features of turbulent flows around SUBOFF, such as the attached boundary layers around the hull, separated vortices from appendages and the wrapped vortices in wakes. The coefficients and power spectral density of the wall pressures obtained are in agreement with the previous numerical results and experimental measurements. It is found that the constructive and destructive interferences of lift and side-force dipoles lead to the deviations of the directivities of instantaneous sound pressures from the lift directions. This is different from noise generated by flows around a circular cylinder, where lift dipoles dominate the radiated noise.

Automated summary

This study investigates the directivity of noise generated by turbulent flows around an underwater vehicle, revealing that the interferences of lift and side-force dipoles lead to deviations in the directivities of instantaneous sound pressures from the lift directions.