简介:长江口海运历史绵远,优势独具,这才成为下西洋船队的航海出发地。夏原吉治水,"制淞通娄",娄江口水势骤增,造就了刘家港,而郑和下西洋远航从这里始发也取得了丰厚的收获。
简介:Sloshingphenomenonintheliquidcargocarriershascaughttheattentionofresearchersastheinteractionbetweenthesloshingwavesandstructureisoneofthekeypointanddifficultyinthestudyofsloshing.Inthispaper,wecapturedthefreesurfacewithavolumeoffluid(VOF)methodandthencalculatedthemotionsandresponsesofthestructurebyadoptingtheReynolds-averagedNavier-Stokes(RANS)equationsforthewholefluiddomain.Withtheuseofuserdefinedfunctions(UDF)inFluent,theinteractionbetweenfluidandstructurewasthensimulated.Asareasonablesimplification,theauthorsstudiedtheresponseofasinglecantileverinatankundersloshingloads;Furtherstudyshouldpaymoreattentiontothemechanismsofinteractionbetweensloshingwavesandelasticstructures.
简介:Inordertostudycavitationcharacteristicsofa2-Dhydrofoil,themethodthatcombinesnonlinearcavitationmodelandmixed-iterationisusedtopredictandanalyzethecavitationperformanceofhydrofoils.ThecavitationelementsarenonlinearlydisposedbasedontheGreenformulaandperturbationpotentialpanelmethod.Atthesametime,themethodthatcombinescavityshapeforfixedcavitylength(CSCL)iterationandcavityshapeforfixedcavitationnumber(CSCN)iterationisusedtoworkoutthethicknessandlengthofhydrofoilcavitations.Throughanalysisofcalculationresults,itcanbeconcludedthatthejumpofpressureandvelocitypotentiallyexistbetweencavitationendareaandnon-cavitationsareaonsuctionsurfacewhencavitationoccursonhydrofoil.Incertainanglesofattack,thecavitationnumberhasanegativeimpactonthelengthofcavitations.Andunderthesameangleofattackandcavitationnumber,thebiggerthethicknessofthehydrofoil,theshorterthecavitationslength.
简介:利用FLUENT软件数值计算了二维柔性鳍作升沉纵摇运动时的推力系数及推进效率,探讨了修正Bose变形方程、均匀载荷和非均匀载荷悬臂梁变形方程等三种柔性模式下纵摇轴位置对摆动鳍推进性能的影响,其中纵摇轴在尾缘处能够获得更大的推力,而最高的推进效率分别对应修正Bose模式下纵摇轴距首缘1/3弦长处和悬臂梁柔性变形模型下纵摇轴距首缘2/3弦长处.同时计算分析了斯特劳哈尔数、最大攻角等参数对柔性鳍水动力性能的影响,建立了最大推力系数和最高推进效率所对应的参数区间,其中低St数的最高推进效率发生在低αmax,高St数的最高推进效率发生在高αmax.