Passenger ship seakeeping optimization by the Overall Motion Sickness Incidence

Wellnessandcomfortonboardareonesofthemostimportantfactorsinshipdesignandmaybe considered thekeycriteriontoachievethebestseakeepingperformancesforpassengervessels.Inthis respect itispossibletoachieveappreciableseakeepingimprovementsbyonlyvaryingseveralhullform parameters,evenifshipmaindimensionsanddisplacementhavebeenalready fixed.Inthepapera new index,namelytheOverallMotionSicknessIncidence(OMSI),defined asthemeanMSIvalueonthe main deck,isproposedandassumedasparametertobeminimizedinasingle-objectiveoptimization procedure.ParametricmodellingisusedtogenerateseveralhullformsderivedbytheNPLsystematic series and,despiteofclassicalmethodswheretheoptimizationproceduresarecarriedoutinregular head waves,variousheadinganglesandtwooperatingscenariosareconsideredinaseaway,described by theJONSWAPSpectrum.Theoptimumhullis finally generatedandrelevantverticalaccelerationsat some criticalpointsonthemaindeck,aswellasheave,pitchandrollspeedpolarplots,arecompared with theparentones.