Hydroacoustic characterization of a marine propeller through the acoustic analogy

This paper deals with the use of the Acoustic Analogy for the prediction of the underwater noise generated by a marine propeller. Different configurations are treated in order to demonstrate the potentiality of such a numerical approach and to analyze the role played by the different noise sources. Unlike analogous aeronautical propellers, it will be shown that the evaluation of the nonlinear quadrupole sources is relevant regardless of the blade rotational speed. On the contrary, the linear sources (thickness and loading noise) due to the propeller are predominant just in a very limited region, while the only appreciable linear contribution affecting the acoustic pressure far field comes from hull scattering effects.