Flow noise induced by an underwater vehicle with appendages

For underwater vehicles, the hull with an axisymmetric revolution body and appendages with hydrofoil profiles exhibit different flow noise characteristics. However, few studies have focused on the noise generated by appendages mounted on the hull or their influence on the noise for the underwater vehicle. In this paper, numerical simulations are carried out for both bare hull and fully appended SUBOFF (name of a standard submarine model for project Submarine Off-board Operations) configurations at a Reynolds number of 1.2 × 107, using large eddy simulation coupled with the Ffowcs Williams and Hawkings equation. The present numerical framework is validated against existing studies, showing good agreement in both flow field and flow noise predictions. The simulation results suggest that the presence of appendages amplifies low-frequency noise on the adjacent hull surface, with the noise primarily propagating laterally from each appendage. Compared to the bare hull SUBOFF, these effects have a significant impact on the noise level and sound directivity of SUBOFF.