Research On Prediction For Propeller Non-cavitating Noise

The battle effectiveness and viability of naval vessels have great relationships withpropeller noise, which can be divided into cavitating noise and non-cavitating noise. With thedevelopment of design levels, the working condition of cavitating noise is not typicalanymore, especially for underwater vessels like submarine. This paper does researches onnon-cavitating noise of propeller, propeller rudder system and duct propeller with the help ofFowcs-Williams Hawkings formula in time domain on the basis of panel method in unsteadyflow.Firstly, numerical computational method based on panel method to predict hydrodynamicperformance in steady flow、unsteady flow and wake field are introduced and used forcalculation，the results and experimental results are compared to prove the effectiveness of themethod. Secondly, the calculate method of paddle-rudder induced velocity is introduced andused as a basis to improve the conventional iterative manner of paddle-rudder interferes. Withthis method, hydrodynamic performance of propeller rudder system and duct propeller inunsteady flow is calculated. In order to prove the effectiveness of the method, the results inideal wake and in presumed wake are calculated and compared with the experimental resultsand other people’s work, with the comparison, conclusion can be made that this numericalcomputational method is steady and effective.Finally, hydrodynamic performance of the propeller is predicted by potential based panelmethod, and pressure distribution on propeller blades and velocity distribution are calculatedand used as inputs for Fowcs-Williams Hawkings formula in time domain to predictnon-cavitating noise of the propeller. By the analysis of non-cavitating noise predictionsresults in different flow, the conclusion can be made that the numerical method is reliable.Further prediction research is also made to predict non-cavitating noise of propeller ruddersystem and duct propeller, the noise character is analyzed, which provides theoretical supportfor the design of low-noise propellers.