【Title】Phase-coupling characteristics of ship radiated-noise demodulation spectrum and application

【Author】CHENG Yusheng~1 ZHANG Baohua~2 GAO Xin~1 ZHOU Jing~1 (1 Navy Submarine Academy Qingdao 266071) (2 Chinese People’s Liberation Army Beijing 100841)

【Abstract】To solve blade number characteristic extraction problem of low noise ships,phase characteristics of ship radiated-noise demodulation spectrum harmonic components using higherorder spectrum analysis were considered.Through analyzing a large number of ship radiated noise data,it points out the existing phase coupling relationship between two or three harmonic components of demodulation spectrum.The phase difference between line spectrum of blade frequency and the sum of line spectrum at shaft frequency and its some harmonic commonly is zero or other constant.Higher-order cumulant is given and higher-order spectrum is simulated when above phase difference is a non-zero constant.The application of phase coupling relationship is studied.According to the higher-order spectral analysis of some weak modulated ship radiated noise,it is indicated that the phase coupling relationship and higher-order spectral analysis can improve the ability to extract propeller parameters,especially for the weak modulation.