船舶设计外文文献翻译

1、外文文献翻译（译成中文1000字左右）：【主要阅读文献不少于5篇，译文后附注文献信息，包括：作者、书名（或论文题目）、（或刊物名称）、出版时间（或刊号）、页码。提供所译外文资料附件（印刷类含封面、封底、目录、翻译部分的复印件等，类的请附网址及原文】ShipsTypedAccordingtoMeansofPhysicalSupportThemodeofphysicalsupportbywhichvesselscanbecategorizedassumesthatthevesselisoperatingunderdesignedconditions.Shipsaredesignedtooperat

2、eabove,on,orbelowthesurfaceofthesea,sotheair-seainterfacewillbeusedasthereferencedatum.Becausethenatureofthephysicalenvironmentisquitedifferentforthethreeregionsjustmentioned,thephysicalcharacteristicsofshipsdesignedtooperateinthoseregionscanbediverse.AerostaticSupportTherearetwocategoriesofvesselst

3、hataresupportedabovethesurfaceoftheseaonaself-inducedcushionofair.Theserelativelylightweightvehiclesarecapableofhighspeeds,sinceairresistanceisconsiderablylessthanwaterresistance,andtheabsenceofcontactwithsmallwavescombinedwithflexiblesealsreducestheeffectsofwaveimpactathighspeed.Suchvesselsdependon

4、liftfanstocreateacushionoflow-pressureairinanunderbodychamber.Thiscushionofairmustbesufficienttosupporttheweightofthevehicleabovethewatersurface.Thefirsttypeofvesselhasflexible“skirts”thatentirelysurroundtheaircushionandenabletheshiptorisecompletelyabovetheseasurface.Thisiscalledanaircushionvehicle(

5、ACV),andinalimitedsenseitisamphibious.Theothertypeofair-cushioncrafthasrigidsidewallsorthinhullsthatextendbelowthesurfaceofthewatertoreducetheamountofairflowrequiredtomaintainthecushionpressure.Thistypeiscalledacaptured-air-bubblevehicle(CAB).Itrequireslesslift-fanpowerthananACV,ismoredirectionallys

6、table,andcanbepropelledbywaterjetsorsupercavitatingpropellers.Itisnotamphibious,however,andhasnotyetachievedthepopularityoftheACVs,whichincludepassengerferries,cross-channelautomobileferries,polar-explorationcraft,landingcraft,andriverinewarfacevessels.HydrodynamicSupportTherearealsotwotypesofvessel

7、sthatdependondynamicsupportgeneratedbyrelativelyrapidforwardmotionofspeciallydesignedhydrodynamicshapeseitheronorbeneaththesurfaceofthewater.Aprincipleofphysicsstatesthatanymovingobjectthatcanproduceanunsymmetricalflowpatterngeneratesaliftforceperpendiculartothedirectionofmotion.Justasanairplanewith

8、(airfoil)producesliftwhenmovingthroughtheair,ahydrofoil,locatedbeneaththesurfaceandattachedbymeansofasurfacepiercingstrut,candynamicallysupportavesselshullabovethwater.PlanninghullsarehullformscharacterizedbyrelativelyflatbottomsandshallowV-sections(especiallyforwardofamidships)thatproducepartialton

9、earlyfulldynamicsupportforlightdisplacementvesselsandsmallcraftathigherspeeds.Planningcraftaregenerallyrestrictedinsizeanddisplacementbecauseoftherequiredpower-to-weightratioandthestructuralstressesassociatedwithtravelingathighspeedinwaves.Mostplanningcraftarealsorestrictedtooperationsinreasonablycl

10、amwater,althoughsome“deepV”hullformsarecapableofoperationinroughwater.HydrostaticSupportFinally,thereistheoldestandmostreliabletypeofsupport,hydrostaticsupport.Allships,boats,andprimitivewatercraftuptothetwentiethcenturyhavedependedupontheeasilyattainedbuoyantforceofwaterfortheiroperation.Thishydros

11、taticsupport,commonlyrecognizedasflotation,canbeexplainedbyafundamentalphysicallawthattheancientphilosopher-mathematicianArchimedesdefinedinthesecondcenturyB.C.ArchimedesPrinciplestatesthatabodyimmersedinaliquidisbuoyedup(oractedupon)byaforceequaltotheweightoftheliquiddisplaced.Thisprincipleappliest

12、oallvesselsthatfloat(orsubmerge)inwater-saltorfresh.Andfromthisstatementthenameoftheshipsinthecategoryarederived;theyaregenerallycalleddisplacementhulls.Althoughthisshiptypeisveryfamiliar,itssubcategorieswarrantspecialdiscussion.Forexample,insomevesselsreasonablyhighspeedmustbecombinedwiththeability

13、tocarrylightcargoortomovemorecomfortablyinroughwaterthanaplanninghull.High-speedplanning-hullcharacteristicscanbemodifiedtoproduceasemidisplacementhullorsemiplaninghull.Thesecompromisecraft,ofcoursenotasfastasfull-planinghullsbutfasterthanconventionaldisplacementhull,musthavemorepowerandlessweightth

14、anthelatter.Suchtypesareobviouslytheresultof“tradeoffs.”Theexamplecitedaboveliesbetweenclear-cutphysicallydefinedcategories-itisnotagoodexampleofavariationofatruedisplacement-typeship.Thelattermustberecognizedprimarilyasadisplacementvessel,anditsvariationsdependprimarilyonthedistributionofbuoyantvol

15、ume-theextentofthedepthandbreadthofthehullbelowthewater.Themostubiquitoustypeofdisplacementshipcanbegenerallyclassifiedasthecommoncarrier,aseagoingvessel.Itmaybeemployedforpassengerservice,lightcargo-carrying,fishingbytrawlingorforhundredsofothertasksthatdonotrequireexceptionalcapacity,speed,submerg

16、ence,orotherspecialperformance.Itisthemostcommonandeasilyrecognizabletypeofship,withmoderatedisplacement,moderatespeeds,moderatetolargelengths,andmoderatecapacities.Itusuallyembodiesthemaximumincruisingrangeandseaworthiness.Itisthe“shipforallseasons.”standardtowhichallothershipclassificationsinthedi

17、splacementcategorymaybereferred.Theclosestrelativetothisstandardvessel,whichplaysacrucialrolenotonlyinworldcommercebutinthesurvivaloftheindustrialworldaswell,isthebulk,oilcarrier,thetanker,orsupertanker.Theseterminologiesarecommonbutunspecific,andinthisdiscussiontheyareinadequate,forwhatwascalledasu

18、pertankerseveralyearsagoistodaynotasupertanker.Theindustryitselfhascreatedafarmoreexplicitnomenclature.Basedupontheindexof1000000tonsoilcargocapacity,thesizecategoriesareLCC(largecrudecarrier),VLCC(verylargecrudecarrier),andULCC(ultralargecrudecarrier).Anytankergreaterthan100000tonsbutlessthan200000

19、isaLCC,thosebetween200000and400000areVLCCs,andthoseover400000areULCCs.Thecurrentnecessityforthesedesignationsbecomesclearwhenwerealizethatbefore1956therewerenotankerslargerthan50000tons,andnotuntiltheearlysixtieswereanyshipsbuiltlargerthan100000tons.In1968thefirstshipover300000tonswasbuilt.Withtheir

20、bulkandenormouscapacity(fourfootballfieldscanbeplacedendtoendononeoftheirdecks),theseshipsaredesignedandbuilttobeprofit-makers,enormouslylong,wide,anddeep,carryingthousandsoftonsofcrudeoilpervoyageattheleastcost.Fewoftheseelephantinetankershavemorethanonepropellershaftofrudder.Theirnavigationbridges

21、arenearlyonequarterofamilefromtheirbows.TheirtopservicespeedissolowthatavoyagefromanArabianoilporttoaEuropeandestinationnormallytakestwomonths.Suchvesselsbelongtoacategoryofdisplacementshipthathasagreatrangeofbuoyantsupport.Theyhaveaverylargeanddisproportionatehullvolumebelowthesurfacewhenfullyloade

22、d.Indeed,thecargoweightfarexceedstheweightoftheshipitself.ThedraftordepthofwaterrequiredforafullyloadedVLCCrunsto50or60feetandtheULCCmaybe80feet.Suchshipsbelongintheexclusivecategoryofdisplacementvesselscalleddeepdisplacementships.Thereexistsanothertypeofdisplacementhullwithextremedraft.However,itis

23、similaritytothecrude-oilcarrieroftheprecedingdiscussiongoesnofurtherthanthat.ThistypeofvesseliscalledtheSWATH(smallwaterplaneareatwinhull).Briefly,thisratherrarebreedofshipisdesignedforrelativelyhighspeedandstableplatforminmoderatelyroughwater.Itsfutureisproblematical,butthetheoryofplacingthebulkoft

24、hedisplacementwellbelowthesurfaceandextendingthesupporttotheabove-waterplatformordeckthroughthenarrowwaterlinefinsorstrutsissound.Twinhullsconnectedbyanupperplatformprovidethenecessaryoperatingstability.Themostsignificantclassofdisplacementhullforspecialapplicationisthesubmarine,avesselforcompletely

25、submergedoperation.Thenatureofthesubmarineandadescriptionofhervariousoperationalattitudes,bothstaticanddynamic,iscoveredinsubsequentchapters.ItisonlynecessaryheretoemphasizethatsubmerisiblevesselsarespecificallydisplacementvesselsapplyingthetheoryofArchimedesPrincipleandallthatitimplies.MultihullVes

26、selsThereisoneothertypeofhullincommonusethathasnotyetbeenmentioned,primarilybecauseitfitsintononeofthecategoriesdescribedbutrathercanexistcomfortablyinany.Thiscraftistheso-calledmultihullvessel-thecatamaranandthetrimaran.Thesevesselsaremostfrequentlydisplacementhullsintheirlargersizes,suchastheSWATH

27、mentionedabove,ormoreconventionally,oceanresearchvesselsrequiringstableplatformsandprotectedareasforlaunchingequipment.Therearealsothetwin-hulledCABvesselsmentionedearlierandhigh-speedplanningcatamarans.Actually,themultihullshipisanadaptationofanyofthebasichullcategoriestoaspecialapplicationthatrequ

28、iresexceptionaltransversestabilityand/ortheinterhullworkingarea.中文翻译：按照物理支撑方式而划分的船舶类型就船舶分类而言，物理支撑形式是基本于船舶在设计情况下进行的假定。船舶设计成在水上、水面或者水下工作，因此气水交界面将用于参考数据。因为前面提到的三个区域的物理环境特性差异很大，设计成在这些区域工作的船舶的物理特性也不同。空气静力支撑有两种类型船舶是靠前身产生的空气垫而支撑在海面之上的。这些相对较轻的船舶具有很高的航速，因为空气阻力远小于水阻力，还有的原因是在告诉航行时不与海浪接触以及采用的柔性密封连接减少了海浪的冲击。这类船舶

29、依靠鼓风机在船底部形成一个低压空气垫。这个空气垫必须足以支撑起水上船舶的重量。第一种类型船的四周具有柔性的“裙”，在船底围成一个空气垫，试船能完全升离水面。这种船成为“气垫船”（ACV），再有些场合是两栖的。另外一种是具有刚性侧壁或薄壳的气垫型船，侧壁伸到水面下，维持气垫压力所需的空气流量就降低了。这种类型的船称为束缚气泡减阻船（CAB）。这种船所需的升力风机功率要小于气垫船的，方向稳定性也更好，并可以由喷水装置或者超空泡螺旋桨推进。此类船非两栖，并且还没有达到像空气船那样推广，如旅客渡船、海峡汽车渡船、极地考察船、登陆艇及内河船等。水动力支撑依靠水动力支撑的船也只有两种类型。水动力是靠专门设

30、计的水动力板在水面下具有快速相对运动而产生的。物理学原理表明任何带来不对称流体的运动物体都会在垂直于运动的方向上产生一个升力。正像具有机翼的飞机在空气中运动能产生升力一样，通过一个穿过水面的支柱而固定在水下的木翼，其水动力可以支撑一般船舶离开水面。滑行船体的特点是具有相对平坦的底部和浅V型剖面（特别是在船中前），高速航行时在局部可以为轻排水量船和小型船艇提供足够的水动力支撑。滑行艇的尺寸与排水量一般都受限制，因为功率重量比和在波浪中航行产生的结构应力大小都有要求。大多数滑行艇都要求在静水中航行，尽管某些深V型船体具有再波浪中航行的能力。静水力支撑最后，是最古老的也是最可靠地支撑类型静水力支撑。

31、一直到20世纪，所有的船、艇和建议的水艇都依靠静水的浮力而工作在水面上。静水力支撑通常称为浮力，可以由公元前二世纪古代哲学及数学家阿基米德发现的物理定律来解释。阿基米德定律指出，浸没在液体中的物体将受到一个等一所排开的液体重量的浮力作用。这一定律适用于浮在水面或在下潜到水中的任何船。水包括海水和淡水。依据这一定律，这类船可以统称为排水型船。尽管这类船非常相似，其详细分类还是有必要进行特别讨论。例如，对某些船，合理的高航速必须与装载轻量货物的能力相结合，或者比滑行艇在波浪中航行更具舒适性。高速滑行船体的特点可以通过修改而产生半排水型船体或半滑行船体。这些折中的船艇，尽管没有全滑行船那样快，但还是

32、比常规的排水型船快。它们需要比排水型船更大的功率和更小的重量。这些类型船很明显是“折中”的结果。上面引证的例子是用物理定义作清晰分类而定义的类型，并不是从其实的排水型船中分化出的船型的一个良好的例子。后者应当认为是排水型船，它的归类主要取决于浮体体积即水下船体长度和宽度X围的分布情况。最常见的是排水型船一般分类为通用海洋运输船，它们可以用作客运、轻货运输、拖网捕鱼或各种不需要特殊舱容、速度、吃水、或其它特殊性能的其他业务。这类船最常见并很容易识别，具有适度的排水量、航速、长度和舱容。它们通常具有最大的航程和最好的适航性，属于“全季节船”，是所有其它排水型船分类时重要参照的标准。在这种标准船型中，最重要的船型是散装油船，油船和其它超级油船，它们不仅在世界贸易中也在全球工业中扮演重要角色。这些术语是普通的但不具体。在该讨论中它们的称呼也是不充分的，