Numerical Simulation and Analysis of Non-cavitation noise Line-spectrum Frequency of Underwater Counter-rotation Propeller

Abstract

This paper analyzes the mechanism of non-cavitation tone noise line-spectrum frequency of counter-rotation propeller. The mechanism is interference effect and circumferential harmonics field effect. According to the generalized acoustic analogy equation, the lift and drag which are caused by the mechanism are the source of noise,the far field sound pressure expression is presented. The line-spectrum frequency and the directionality of sound pressure have been analyzed. The results show: the predication line-spectrum frequency could be written as f=sAPF+mBPF1+nBPF2; sound pressure radiation is 8-shaped distribution and the Bessel function's peak condition is a necessary condition for line-spectrum. The counter-rotation propeller's non-cavitation condition is numerically simulated using RNG k-e turbulent model、 sliding mesh model and kFW-H equation. The results shows that RNG k-e Turbulent model has the better accuracy than Realizable k-e turbulent model, and the counter-rotation propeller non-cavitation line-spectrum frequency and the directionality of sound pressure are got by this method which agree well with the result of Academic prediction.