简介:Inordertominimizetheharmcausedbytheinstabilityofaplaningcraft,amotionpredictionmodelisessential.ThispaperanalyzedthefeasibilityofusinganMGM(1,N)modelingreysystemtheorytopredictplaningcraftmotionandcarriedoutthenumericalsimulationexperiment.Accordingtothecharacteristicsofplaningcraftmotion,arecurrenceformulawasproposedoftheparametermatrixofanMGM(1,N)model.Usingthisformula,datacanbeupdatedinreal-timewithoutincreasingcomputationalcomplexitysignificantly.TheresultsofnumericalsimulationshowthatusinganMGM(1,N)modeltopredictplaningmotionisfeasibleandusefulforprediction.Sothemethodproposedinthisstudycanreflecttheplaningcraftmotionmechanismsuccessfully,andhasrationalandeffectivefunctionsofforecastingandanalyzingtrends.
简介:Green-Naghdi(G-N)theoryisafullynonlineartheoryforwaterwaves.SomeresearcherscallitafullynonlinearBoussinesqmodel.DifferentdegreesofcomplexityofG-Ntheoryaredistinguishedby"levels"wherethehigherthelevel,themorecomplicatedandpresumablymoreaccuratethetheoryis.IntheresearchpresentedhereacomparisonwasmadebetweentwodifferentlevelsofG-Ntheory,specificallylevelIIandlevelIIIG-Nrestrictedtheories.AlinearanalyticalsolutionforlevelIIIG-Nrestrictedtheorywasgiven.WavesonaplanarbeachandshoalingwaveswerebothsimulatedwiththesetwoG-Ntheories.ItwasshownforthefirsttimethatlevelIIIG-Nrestrictedtheorycanalsobeusedtopredictfluidvelocityinshallowwater.AlevelIIIG-NrestrictedtheoryisrecommendedinsteadofalevelIIG-Nrestrictedtheorywhensimulatingfullynonlinearshallowwaterwaves.