船舶专业英语(课文+翻译)

Chapter1ShipDesign（船舶设计）Lesson2ShipsCategorized（船舶分类）2.1Introduction（介绍）Theformsashipcantakeareinnumerable.一艘船能采用的外形是不可胜数的Avesselmightappeartobeasleekseagoinghotelcarryingpassengersalongtosomeexoticdestination;afloatingfortressbristlingwithmissilelaunchers;。oranelongatedboxtransportingtanksofcrudeoilandtoppedwithcomplexpipeconnections.一艘船可以看做是将乘客一直运送到外国目的地的优美的远航宾馆。竖立有导弹发射架的水面堡垒及甲板上铺盖有复杂管系的加长罐装原油运输轮Noneofthesedescriptionsofexternalappearance,however,doesjusticetotheshipsystemasawholeandintegratedunit所有这些外部特点的描述都不能说明船舶系统是一个总的集合体self-sufficient,seaworthy,andadequatelystableinitsfunctionasasecurehabitatforcrewandcargo.——船员和货物的安全性功能：自给自足，适航，足够稳定。Thisistheconceptthatthenavalarchitectkeepsinmindwhendesigningtheshipandthatprovidesthebasisforsubsequentdiscussions,notonlyinthischapterbutthroughouttheentirebook.这是一个造船工程师设计船舶使必须记住的、能为以后讨论提供根据的观念，不仅涉及本章也贯穿全书。Inordertodiscussnavalarchitecture,itishelpfultoplaceshipsincertaincategories.Forpurposesofthistext,shipsareclassifiedaccordingtotheirmeansofphysicalsupportandtheirdesignedpurposes.将船舶分成一些特定的种类来讨论造船工程是有好处的。本文的目的就是根据船舶物理支撑方式和设计目的来将它们分类。2.2ShipsTypedAccordingtoMeansofPhysicalSupport（根据物理支撑方式来分类）Themodeofphysicalsupportbywhichvesselscanbecategorizedassumesthatthevesselisoperatingunderdesignedconditions-Shipsaredesignedtooperateabove,on,orbelowthesurfaceofthesea,sotheair-seainterfacewillbeusedasthereferencedatum.船舶按物理支撑的分类方式假设，船舶是在设计工况的条件下航行。船舶预定在海面上，海面中或海面以下航行，因此使用空气与水的接触面作为基准面。Becausethenatureofthephysicalenvironmentisquitedifferentforthethreeregionsjustmentioned,thephysicalcharacteristicsofshipsdesignedtooperateinthoseregionscanbediverse.由于上面提到的三个区域中物理环境的本质相差很大，所以那些区域中的船的物理特性也不同。AerostaticSupport（空气静力支撑）Therearetwocategoriesofvesselsthataresupportedabovethesurfaceoftheseaonaself-inducedcushionofair.Theserelativelylightweightvehiclesarecapableofhighspeeds,sinceairresistanceisconsiderablylessthanwaterresistance,andtheabsenceofcontactwithsmallwavescombinedwithflexiblesealsreducestheeffectsofwaveimpactathighspeed.有两种靠自身诱导的气垫浮于海面上的船。这些重量相对轻的船能够高速航行，这是因为空气阻力比水阻力小得多，而且船舶高速航行时，弹性密封圈没有与小波浪接触，因而降低了了波浪冲击的影响。Suchvesselsdependonliftfanstocreateacushionoflow-pressureairinanunderbodychamber.这种船依靠升力风扇在船体水下部分产生了低压气垫。Thiscushionofairmustbesufficienttosupporttheweightofthevehicleabovethewatersurface.这种空气气垫必须足够支撑水面上方船的重量。Thefirsttypeofvesselha.sflexibleskirtsthatentirelysurroundtheaircushionandenabletheshiptorisecompletelyabovetheseasurface.第一种船有完全围绕在气垫周围并且能够使船完全漂浮在水面以上的弹性围裙。Thisiscalledanaircushionvehicle(ACV),andinalimitedsenseitisamphibious.它被称为气垫船（ACV），某种有限的程度上适用于两栖。Theothertypeofair-cushioncrafthasrigidsidewallsorthinhullsthatextendbelowthesurfaceofthewatertoreducetheamountofairflowrequiredtomaintainthecushionpressure.另一种气垫船带有刚性侧壁，且有延伸到水下能够减小空气流量的瘦船体，该气流用来维持气垫压力。Thistypeiscalledacaptured-air-bubblevehicle(CAB).这种类型船称为束缚气泡减阻船Itrequireslesslift-fanpowerthananACV,ismoredirectionallystableandcanbepropelledbywaterjetsorsupercavitatingpropellers.相对于ACV来说，它需要较低的升力风扇动力,航向稳定性更好，并且能使用喷水推进器和超空泡螺旋桨。Itisnotamphibious,however,andhasnotyetachievedthepopularityoftheACVs,whichincludepassengerferries,cross-channelautomobileferries,polar-explorationcraft,landingcraft,andriverinewarfarevessels.但是，它不是两栖用途的，也还没有ACVs那么广的适用范围，适用范围包括游客渡轮，横越海峡车客渡轮，极地考察船，登陆舰及内河舰艇。HydrodynamicSupport（水动力支撑）Therearealsotwotypesofvesselsthatdependondynamicsupportgeneratedbyrelativelyrapidforwardmotionofspeciallydesignedhydrodynamicshapeseitheronorbeneaththesurfaceofthewater.也有两种类型船，它们依赖通过船的相对高速前进运动来产生动力支持，这种船型的水上和水下部分的形状都经过特殊设计。Aprincipleofphysicsstatesthatanymovingobjectthatcanproduceanunsymmetricalflowpatterngeneratesaliftforceperpendiculartothedirectionofmotion.一个物理定理这样陈述：任何运动的物体都能造成不均匀的流态，产生一个垂直于运动方向的升力。Justasanairplanewith(airfoil)producesliftwhenmovingthroughtheair,ahydrofoillocatedbeneaththesurfaceandattachedbymeansofasurfacepiercingstrut,candynamicallysupportavesselshullabovethewater.正如装有空气翼的飞机在空气中移动时气翼上能产生一个升力一样，位于水面以下且其上固定有穿透水面的柱体的水翼，能够动态支撑水面以上的船体。PlaninghullsarehullformscharacterisedbyrelativelyflatbottomsandshallowV-sections(especiallyforwardofamidships)thatproducepartialtonearlyfulldynamicsupportforlightdisplacementvesselsandsmallcraftathigherspeeds.滑行船体的特征是底部相对较平，横剖面呈浅V形（尤其是船的前半部分）。这种形状特点能够使船产生偏近满动力支持，适用于使小排水量船和高速小艇。Planingcraftaregenerallyrestrictedinsizeanddisplacementbecauseoftherequiredpower-to-weightratioandthestructuralstressesassociatedwithtravelingathighspeedinwaves.一般说来，滑行船体的尺寸和排水量有限制。这是因为需要满足动力和重量的比率要求，以及在波浪中高速航行时的结构应力要求。Mostplaningcraftarealsorestrictedtooperationsinreasonablycalmwater,althoughsomedeepVhullformsarecapableofoperationinroughwater.虽然有一些‚深V型剖面船能够在恶劣的海况中航行，但大多数滑行船体也都限制在相当平静的水面上航行。Lesson3PrincipalDimensions（主尺度）3.1PrincipalDimensions（主尺度）Beforestudyingindetailthevarioustechnicalbranchesofnavalarchitectureitisimportanttodefinevarioustermswhichwillbemadeuseofinlaterchapters.Thepurposeofthischapteristoexplainthesetermsandtofamiliarisethereaderwiththem.在系统的学习船舶工程不同的技术分支之前，应该定义一些术语以便于后面章节使用，这很重要。本章旨在于解释这些术语，并且让读者熟悉它们。Inthefirstplacethedimensionsbywhichthesizeofashipismeasuredwillbeconsidered;