Study of noise control for an industrial jet

For controlling the jet noise, the most effective way is to reduce the noise directly form the acoustic source. Based on the principle of jet noise production, the paper theoretically analyzes the influence of nozzle’s shape on noise. Properly changing the shape of the nozzle can reduce the vertical gradient of flow velocity along the jet’s axial direction, and thus weaken the intensity of the turbulence which results in reduction of jet noise. Numerical computation indicates that the improved nozzle can obviously reduce the velocities in the flow field. The experiment verifies that the jet noise can be effectively inhibited by modifying the flow field, and the sound level can be reduced by 3~4 dB (A).