Calculation and analysis of radiated noise caused by propeller-induced pressure fluctuations for SWATH ship

  Objectives  The radiated noise caused by propeller-induced pressure fluctuations of SWATH ship is studied.

  Methods  Due to the difference between the common load application ways and the actual situation, as well as the interaction between the two propellers, an acoustic-structure coupling numerical model of a whole SWATH ship was established. The radiated noise caused by propeller-induced pressure fluctuations was calculated using the ship model test results, and the influence of different load application ways and the phase difference between the excitation torque of two propellers was quantitatively analyzed.

  Results  The results show that the radiated noise is mainly caused by the blade frequency component, which is related to the bending mode of the blade. The influence of different load application ways is remarkable. With regard to the actual load distribution, the results obtained by common load application ways such as concentrated force or uniformly distributed pressure are larger, and applying the concentrated force leads to the largest result. The phase difference between the excitation torque of two propellers also has a significant effect. The radiated noise is largest when the two propellers are in the same phase, and decreases gradually with the increase of phase difference, and the noise is smallest when the two propellers in the opposite phase.

  Conclusions  The study in the paper can provide reference for prediction and control of radiated noise caused by propeller-induced pressure fluctuations for SWATH ship.