Flow Noise Calculation and Suppression for Sonobuoy

The sea waves can make sonobuoy vibrate in the vertical direction. The vibration can create flow noise which will affect the work performance of the sonobuoy. It can be suppressed by adding flexible cable to the structure of the sonobuoy. In this paper, we first establish a theoretical model used in calculating the flow noise of sonobuoy to analyze the corresponding relationship between the flow noise and the vibration velocity. Then we establish a forced vibration model of the sonobuoy to analyze the effect of flexible cable on suppressing flow noise caused by vibration of the sonobuoy. According to the simulation results calculated by the flow noise theoretical calculation model, we find that the spectrum level of the flow noise increases with the increase of the flow velocity. According to the simulation result calculated by the sonobuoy vibration model, we find that choosing an appropriate elastic coefficient for the flexible cable can effectively suppress the vibration of the sonobuoy caused by the sea waves. As a consequence, the flow noise of the sonobuoy can be reduced effectively.