Objective  This paper aims to study the overall acoustic radiation properties of a submarine hull-propeller system with a seven-blade highly skewed propeller working under different operating conditions.

  Methods  Taking the SUBOFF submarine model and a highly skewed propeller as the research object, the large eddy simulation (LES) and acoustic finite element method are adopted, and Fluent fluid calculation software and LMS Virtual.Lab acoustic simulation software are used to carry out joint simulation calculation.

  Results  The results show that the velocity and pressure distributions in the bow, conning tower, stern rudder and propeller area change the most when the submarine has advance speed. The noise propagation direction of the whole system has the highest sound pressure level (SPL) in a certain direction of the hull's circumference, followed by the aft direction. When the submarine has no advance speed, the noise of the coupling system is related to the rotating action of the propeller, and there is a peak at the 440 Hz frequency, which exceeds the SPL under other operating conditions.

  Conclusions  The three regions of the bow, conning tower and stern rudder are the key regions that generated pressure pulsation, which is closely related to the advance speed of the submarine. In the low frequency band, the propeller noise is mainly generated by the bow, conning tower and stern rudder. In the middle and high-frequency bands, the overall submarine hull-propeller noise also begins to have an effect, and the total SPL increases gradually with the increase in frequency.