简介:Tosolvebladenumbercharacteristicextractionproblemoflownoiseships,phasecharacteristicsofshipradiated-noisedemodulationspectrumharmoniccomponentsusinghigherorderspectrumanalysiswereconsidered.Throughanalyzingalargenumberofshipradiatednoisedata,itpointsouttheexistingphasecouplingrelationshipbetweentwoorthreeharmoniccomponentsofdemodulationspectrum.Thephasedifferencebetweenlinespectrumofbladefrequencyandthesumoflinespectrumatshaftfrequencyanditssomeharmoniccommonlyiszeroorotherconstant.Higher-ordercumulantisgivenandhigher-orderspectrumissimulatedwhenabovephasedifferenceisanon-zeroconstant.Theapplicationofphasecouplingrelationshipisstudied.Accordingtothehigher-orderspectralanalysisofsomeweakmodulatedshipradiatednoise,itisindicatedthatthephasecouplingrelationshipandhigher-orderspectralanalysiscanimprovetheabilitytoextractpropellerparameters,especiallyfortheweakmodulation.