Numerical Prediction on Non-cavitating Noise of a New Type of Ducted Propeller

The calculation of the hydrodynamic performance of the propeller and the prediction of the noise performance can provide theoretical support for the efficient advancement of the underwater vehicle and the low noise design. In this paper, a new type of ducted propeller is modelled based on the ducted propeller of KA4-70+19A. It is a scalable deflector inside of the duct which is used for producing the lateral force. Then the numerical simulation of open water performances and unsteady flow is carried out with DES model and the pressure fluctuation on blade surface is studied as the inputs for numerical prediction on non-cavitating noise. Noise at a series of field points along axial and radial direction of the two ducted propellers above are simulated. The calculated sound pressure level directivity characteristics and downstream axial field point’s broadband sound pressure spectrum are compared between the two ducted propellers. At the end, different sizes and shapes of deflector are studied to see the influence on the open water performance and the non-cavitating noise.