简介:Inthispaper,addedresistancesactingonahullofnonballastwatership(NBS)inhighwavesisdiscussed.ThenonballastwatershipsweredevelopedatthelaboratoryoftheauthorsatOsakaPrefectureUniversity,Japan.Inthepresentpaper,theperformancesofthreekindsofbowshapesdevelopedfortheNBSweretheoreticallyandexperimentallyinvestigatedtofindthebestoneinhighwaves.Inpreviouspapers,anoptimumbowshapefortheNBSwasdevelopedincalmwaterandinmoderatedwaves.Fora2mmodelforexperimentsandcomputations,thewaveheightis0.02m.Thismeansthatthewaveheightis15%ofthedraftoftheshipinfullloadconditions.Inthispaper,addedresistancesinhighwavesupto0.07mfora2mmodelor53%ofthefullloaddraftareinvestigated.Insuchhighwaveslinearwavetheorieswhichhavebeenusedinthedesignstageofashipforalongtimemaynotworkwellanymore,andexperimentsaretheonlyeffectivetooltopredicttheaddedresistanceinhighwaves.Withthecomputationsforwaves,theshipisinafullycapturedconditionbecauseshorterwaves,λ/Lpp〈0.6,areassumed.
简介:由使用ABAQUS/Explicit,动态过程一近海风汽轮机(任何东西)乘在前面方向的5000DWT的一艘轮船受灾被模仿。任何东西位于一种综合安装技术构造的一个大规模对桶基础。根据模拟结果,在轮船碰撞下面,塑料地区的某个范围出现在桶基础,和具体塑料地区的弧转变结构的一个本地区域以内严重被损坏。因为任何东西塔的压力水平是相对低的,OWT塔是影响的更少。因为短舱和片的团直到400t,大惯性的力量在OWT塔的顶被产生。塔的排水量在在在惯性的力量的行动下面的1s的结束的轮船碰撞的相反的方向。仅仅在轮船鞠躬有次要的损坏。大多数动能被转变成塑料驱散并且由桶基础的弧转变结构吸收了。
简介:Inthispaper,numericalpredictionofshipmotionresponsesinlong-crestirregularwavesbytheURANS-VOFmethodispresented.Awhitenoisespectrumisappliedtogeneratetheincomingwavestoevaluatethemotionresponses.Theprocedurecanreplaceadecadeofsimulationsinregularwavewithonesingleruntoobtainacompletecurveoflinearmotionresponse,considerablyreducingcomputationtime.Acorrectionprocedureisemployedtoadjustthewavegenerationsignalbasedonthewavespectrumandachievesfairlybetterresultsinthewavetank.Threeshipmodelswithfivewaveconditionsareintroducedtovalidatethemethod.Thecomputationsinthispaperarecompletedbyusingthesolvernaoe-FOAM-SJTU,asolverdevelopedforshipandoceanengineeringbasedontheopensourcecodeOpenFOAM.Thecomputationalmotionresponsesbytheirregularwaveprocedurearecomparedwiththeresultsbyregularwave,experimentsandstriptheory.Transferfunctionsbyirregularwavecloselyagreewiththedataobtainedintheregularwaves,showingnegligibledifference.Thecomparisonbetweencomputationalresultsandexperimentsalsoshowgoodagreements.TheresultsbetterpredictedbyCFDmethodthanstriptheoriesindicatethatthismethodcancompensatefortheinaccuracyofthestriptheories.Theresultsconfirmthattheirregularwaveprocedureisapromisingmethodfortheaccuratepredictionofmotionresponseswithlessaccuracylossandhigherefficiencycomparedwiththeregularwaveprocedure.