Contrast experiments on the propeller noise of the Kappel propeller and the conventional propeller

To test the noise performance of the Kappel propeller, background noise and propeller noise contrast tests are carried out in the NUE cavitation tunnel. Both wet condition noise and the cavitation noise of the two propellers are measured in the tests under sixteen different working conditions. The analysis based on the measurement results indicates that the acoustics performance of the NEU cavitation tunnel satisfies the requirements of the tests, and higher signal-to-noise ratio can be achieved in the frequency range between 1 kHz and 20 kHz. The SPL of the Kappel propeller noise equals to the conventional propeller noise under the wet condition. With the same cavitation number, the SPL of the Kappel propeller cavitation noise is higher than that of the conventional propeller. Meanwhile, the pattern of the Kappel propeller cavitation is more precise than that of the conventional propeller. It is concluded that the cavitation performance of the Kappel propeller is poorer than that of the conventional propeller. To improve the cavitation performance, the relationship between pitch and camber should be comprehensively considered in the process of Kappel propeller designing.