Study On Sound Generation And Numercial Simulation Of Aerodynamics Siren

The principles of some kinds of aeroacoustic noise and aeroacoustic sources were studied and the mechanism of an aeroacoustic siren source was proposed; the experiment methods and numerical study were put on to research the aeroacoustics; and the numerical study was compared with the results of the experiment research, and the acoustic theory of the intervene noise and vortical noise are regarded as the key to find out the principle of the aeroacoustic source.The experiment methods were used and different kind of the sirens were designed to study the factors of the frequency of the aeroacoustic source. It is concluded that the frequency is decided by the amount of the blades and the rotate speed, and has nothing on with the other parameters. The results is in favor of the further acoustic theory study.The numerical method was used and The CFD technology was proposed to analyze the numerical study of an aeroacoustic source in this paper. The Navier-Stokes equation and the RNG turbulence model method was applied, also an interface was set up between the revolving component and the stationary one based on the sliding mesh principles in the numerical study. Then, the time-domain and frequency-domain analyses on fluctuating of pressure in the flow field were carried out. And the numerical results were compared with our experimental data, and the dependability was proved, at the same time ,the work of this paper is useful for further study of this aerodynamic source.