Noise Prediction of the Cavitation Tunnel

The present paper is concerned with the prediction technique of back ground noise in the cavitation tunnel generated by flow-induced noise and the mechanical noise. To predict the back ground noise level, acoustic power balance method has been applied as computation technique. This method is based on the balance of acoustic power flow propagating left and right hand direction individually, in each element and among adjacent elements. In order to establish balance equations, many acoustic characteristics can be considered which are absorption, transmission, attenuation, reflection, radiation, noise sources and so on. Then the coefficient for these characteristics have been estimated by the measured data of a cavitation tunnel in MHI (Mitsubishi Heavy Industries, Ltd.) in Japan. Calculation results show good agreement with the measured values of another cavitation tunnel in IHI (Ishikawajima-Harima Heavy Industries, Ltd.) in Japan.