Numerical Analysis of Flow Noise Characteristics of Pump-jet Propeller Based on Different Turbulence Models

Flow noise refers to the noise caused by the disturbance in the fluid mechanical turbulent boundary layer and the pulsating pressure on the wall surface, which is mainly generated in the boundary layer of the turbulent flow. In this paper, a pump-jet propeller is taken as the research object. Firstly, based on the CFD method, ANSYS CFX software is used to simulate the hydrodynamic performance of pump-jet propellers with different turbulence models at different speed ratios. Then, based on finite element/infinite element technology and based on the principle and application of Lighthill's [1]-[2] acoustic analogy theory, an acoustic calculation model was established. By using the acoustic simulation software ACTRAN, the acoustic noise simulation was carried out for the LES model, and the sound source distribution around the propeller was obtained at different speeds. The results show that with the increase of the monitoring distance, the sound pressure level gradually decreases, showing the attenuation characteristics, and the attenuation of the head, tail and radial directions of the propeller is consistent. Secondly, the sound pressure level of the sound field around the propeller shows a certain directivity, as the rotor speed increases, the total sound pressure level of the sound field around the propeller gradually increases, and there is consistency at different speeds.