简介:为了提供指令因为推进器的计算用身体在壳推进器相互作用的学习导致了速度,强迫途径,三个方法被用来计算推进器导致的速度:1)自我推进测试的平均Reynolds的海军司烧(RANS)模拟,2)推进器的RANS模拟开的水测试,并且3)推进器的动量理论。从开始的二个方法的结果对试验性的数据被验证估计计算流动领域的精确性。戳身份方法被采用获得进展速度,它然后被用来导出推进器来自全部的速度地的导致的速度。开始的二条途径计算的结果是靠近的,当那些显著地从动量理论被过高估计时。介绍结果能证明为用身体力量途径的自我推进的另外的计算有用。
简介:Thewave-inducedverticalshipmotionsandbendingmomentsofadoublehull-oiltankerinrealisticfloodingconditionsarestudied.Thescenariosinvestigatedarerepresentedbywateringressintothestarboardballasttanksforcollisiondamagecasesandbothstarboardandportsideballasttanksforgroundingsituations.Seakeepingcomputationsareperformedforeightdamagescenariosandfortheintactcondition,eachcorrespondingtodifferentchangesindisplacement,trim,andheel.Foreachofthedamageconditions,transferfunctionsofverticalmotionsandloadsarecalculatedusingapotentiallinear3Dpanelhydrodynamiccodeinthefrequencydomainthatincludeseffectofthemotionofthewaterinfloodedtanks.AMATLABcodeisdevelopedtofacilitateautomatedhydrodynamicsimulationofmanydamagescenarios.Verificationofseakeepingresultsisperformedbycomparingtransferfunctionswithresultsofthepreviousstudy.Wave-inducedverticalresponsesofdamagedshiparethencomparedtothoseofintactshipusingtwospectral-basedmethodsoriginatingfromuncertaintyanalysisofwaveloads,whichareconvenienttoolstoassessconsequencesofdamageonshort-termshipresponses.Generally,observedtrendisthatverticalwave-inducedresponsesofdamagedshipconvergetowardthoseofintactshipwithincreasingwaveperiod.Fairlysmalldifferencesbetweenresponsesofasymmetricallydamagedshipwithrespecttothesymmetricalincomingwavedirectionsarefound.Theresultsofthestudyareanefficientmethodforseakeepingassessmentofdamagedoiltankersandtheframeworkforevaluatingconsequencesofdamagescenarios,headingangles,andseaconditionsonseakeepingresponsesofdamagedships.Theresultscanbeusedtodecideiftheintactshipmodelcanbeusedinsteadofthedamagedonefortheemergencyresponseprocedureorfortheriskassessmentstudieswhenmodelingandcomputationaltimerepresentimportantlimitations.
简介:Theshipmotionsandwave-inducedloadsofanewtypeofriver-to-seashipareinvestigatedexperimentallyandnumerically.Ariver-to-seashipisanunconventionaltypeofcontainershipcharacterizedbyhighbreadthtodraftratioandlowlengthtobreadthratio,whichmakesitmorepronetohydroelasticitythanconventionalshipsofthesamesize.Asegmentedmodelwastestedundertwoloadingconditions,namely,ballastandloadedconditions,todeterminetheverticalmotionsandwave-inducedloadsundereachcondition.Resultsarecomparedwithnumericalsimulationsinthefrequencydomain.Thewave-inducedresponsesarecalculatedbyanonlineartimedomaincodeateachtimestep.Theresponseamplitudeoperatorsofverticalshipresponsesinregularwavesareanalyzed,andthewave-inducedresponsesareconsistentwiththeexperimentalresults.
简介:InthepresentstudyanattempthasbeenmadetoinvestigatetherelationshipbetweenthevariationsinthefoulingassemblageandcorrosionbehaviourofHSLAsteelatthreecoastallocationsintheGulfofMarmar,India,overaperiodof24months.OysterfoulingwasdominantintheTuticorinopensea,whilebarnacleswerethemajorfoulantsintheTuticorinharbourandMandapam.ThefoulingloadintheTuticorinwaterswashigherwhencomparedtotheMandapamwaters.Thecorrosionratesdecreasedprogressivelywiththeimmersiontimeatallthreetestlocations.IntheTuticorinopensea,thecorrosionrateswerehigherwhencomparedtotheothertwolocationsthroughoutthestudyperiod.ThesurfaceofthecouponswascharacterizedbycrevicesbeneaththehardfoulersintheTuticorinharbourandMandapam,whereasintheTuticorinopensea,thecouponsexperiencedcrevicesofatunnelingnature.Thepercentageofthelossofthetensilestrengthincreasedwithtimeatallthetestlocations.