Abstract: The generation mechanism of non-cavitation noise line-spectrum frequency of counter-rotation propeller is analyzed. The mechanism is the interference effects of front and rear propellers and the circumferential harmonic field effect. According to the generalized acoustic analogy equation, the lift and drag which are caused by the mechanism are the sources of noise. The far field sound pressure expression is presented. The line-spectrum frequency and the directionality of sound pressure are analyzed. The results show that the predicated line-spectrum frequency could be written as f=sAPF+pBPF₁+hBPF₂; sound pressure radiation is distributed as“8”-shape, and the peak condition of Bessel function is a necessary condition for line-spectrum generation. The non-cavitation of counter-rotation propeller is numerically simulated using RNG k-ε turbulence model, sliding mesh model and FW-H equation. The results shows that RNG k-ε turbulent model has the better accuracy than Realizable k-ε turbulent model. The non-cavitation line-spectrum frequency of counter-rotation propeller and the directionality of sound pressure are got by using the proposed method, which agree well with the theoretical results.

Key words: acoustics, generalized acoustic analogy equation, counter-rotation propeller, non-cavitation line-spectrum frequency, RNG k-ε turbulence model, numerical simulation