AircraftLandingGearLayouts飛起架計(jì)中文對(duì)）發(fā)布人：圣才學(xué)習(xí)網(wǎng)發(fā)布日期：2010-06-2514:36共292瀏覽[大][中[小Mostaircrafthavethreegear．許多現(xiàn)代飛機(jī)使用三點(diǎn)式起落架。Twomainlandinggearstrutslocatednearthemiddleoftheaircraftusuallysupportabout90%oftheplane’sweightwhileasmallernosestrutsupportstherest．重心附近的兩個(gè)大的主輪，承擔(dān)約90%的重量，小輪子承擔(dān)余下部分。Thislayoutismostoftenreferredasthe"tricycle"landinggear．，therearenumerousotherdesignsthathavebeenusedovertheandeachitsownadvantagesanddisadvantagesLet’stakeacloseratthevariousundercarriageoptionsavailabletoengineers．目前的飛機(jī)以前三點(diǎn)起落架為主，讓我們來(lái)回顧一下后三點(diǎn)起落架及其優(yōu)缺點(diǎn)。（意譯）TailwheelTaildraggerGear后三點(diǎn)尾式與后三點(diǎn)尾橇式起架Thoughthetricyclearrangementmaybemostpopulartoday，wasnotalwayscase．Thetailwheelundercarriageaircraftdesignforthefirstfourdecadesofflightandisstillwidelyusedonmanysmall－engineplanes．雖然前三點(diǎn)起落架比較普遍是幾十年前的飛機(jī)當(dāng)?shù)脑S多小型飛機(jī)是使用后三點(diǎn)起落架的。Thetaildraggerarrangementconsistsoftwomaingearunitslocatednearthecenterofgravity（）thatsupportthemajorityoftheplane’s后三點(diǎn)起落架，由兩個(gè)在重心靠前位置的主輪支持大部分的飛機(jī)重量。Amuchsmallersupportisalsolocatedattherearthefuselagesuchthattheplaneappearstodragitstail，hencethename一個(gè)非常小的尾輪裝置在機(jī)身，看上去這個(gè)小輪子是被拖著走，所以，英文Taildragger也因此而得名。Thistailunitisusuallyaverywheelbutcouldevenbeaskidonaverysimple它即可以是一個(gè)小尾輪，也可以是一個(gè)尾橇。1/后三點(diǎn)起落架Whatmakesformoflandinggearmostattractiveisitssimplicity后三點(diǎn)起落架最吸引人的優(yōu)點(diǎn)就是“簡(jiǎn)潔”。Thegearareusuallyrelativelylightweight，andthetwomaingearcanalsobeeasilyencasedinstreamlinedfairingstolowdraginflight后三點(diǎn)起落架通常重量都比較輕。兩支主輪子可以配置整流置用來(lái)減小飛行中的阻力。Anotherpotentialadvantageresultsfromthefacttheplaneisalreadytiltedtoalargeangleofattackasitrollsdownrunway．另一個(gè)潛在的優(yōu)點(diǎn)，是飛機(jī)在跑道滑行時(shí)，機(jī)翼已經(jīng)有一個(gè)較大的迎角。Thisattitudehelpstogreaterliftandreducethedistanceneededfortakeofforlanding合適的大迎角，有利于在較低的速度下產(chǎn)生足夠的升力，以便于減少起飛滑跑距離。Thisattitudeisalsoanadvantageonpropeller－drivenplanessinceprovidesalargeclearancethetipsandtheground．對(duì)牽引式螺旋槳飛機(jī)，機(jī)頭向上抬起，使螺旋槳不會(huì)接觸跑道。（意譯）Furthermoretaildraggerplanesaregenerallyeasierforgroundpersonnelmaneuveraroundconfinedspacesahangar．同時(shí)，后三點(diǎn)起落架的飛機(jī)，更便于地勤人員把飛機(jī)拖到停機(jī)棚等窄小的空間里。However，thegreatestofthislandinggearlayoutitshandling．2/另一方面，后三點(diǎn)起落架也有一個(gè)最大的缺陷——著陸時(shí)的操縱（characteristics）Thisdesignisinherentlyunstablebecausetheplane’scentergravityislocatedbehindthetwomaingear造成此天生缺陷的原因，是因?yàn)閮芍恢鬏喸谥匦牡那懊?。Iftheplaneislandingandonewheeltouchesdownfirst，theplaneatendencytoveeroffinthedirectionofthatwheel如果著陸時(shí)起落架只有一只主輪前觸地，這時(shí)，飛機(jī)有向此輪子一邊轉(zhuǎn)彎傾向。Thisbehaviorcancausetheaircraftturninanincreasinglytighter"groundloop"thatmayeventuallyresultinscrapingawingtiponthecollapsingthegearveeringoffthe．嚴(yán)重時(shí)，這種轉(zhuǎn)彎的傾向（groundloop將可能使翼尖觸地、起落架受損、滑出跑道。Landingataildraggercanbedifficultsincethepilotmustlineuphisapproachverycarefullywhilemakingconstantrudderadjustmentstotheplaneonastraightpathuntilitcomestostop．這就要求在飛機(jī)著陸觸地前，需要使用方向舵修正自己的航線，使它能夠筆直的滑翔直到安全觸地。Manytaildraggerdesignsalleviatethesehandlingproblemsbyfittingatailwheelthatcanbelockedinsteadofona．thetailwheelhelpskeeptheplaneinastraightduringlanding．使用尾橇，能減輕這種現(xiàn)象。（意譯）前三點(diǎn)起落架與后三點(diǎn)起落架的安定性對(duì)比3/Anotherdisadvantageofthetaildraggerispoorpilotduringtaxiingsinceheisforcedtopeeroveranosethatistiltedupwardasteepangle．后三點(diǎn)起落架的另一個(gè)缺點(diǎn)多飛機(jī)在地面滑跑，頭向上翹起時(shí)會(huì)響飛行員的視線譯）Itisalsooftentoloadorunloadheavycargosbecauseoftheslopeofthecabinfloor．對(duì)于貨機(jī)，飛機(jī)的迎角不利于貨物的裝卸。pilotsandpassengersareforcedtowalkuphillduringboardingdownhillafterarrival此問(wèn)題，對(duì)于乘客來(lái)說(shuō)，也是一樣的道理。（意譯）Manyaircraftrelyongravitybringfuelfromtothesomeplaneshavebeenknownhavedifficultystartingtheengineitisuphillfromthefuel發(fā)動(dòng)機(jī)抬起，有時(shí)也不利于供油，造成啟動(dòng)困難。道格拉斯DC－的三點(diǎn)起落GoodexamplestaildraggeraircrafttheSpitfireand－3ofWarII．后三點(diǎn)起落架的典型例子：噴火戰(zhàn)斗機(jī)、道格拉斯－3TricycleNosewheel前三點(diǎn)起架Nowthemostpopularlandinggearthetricycleundercarriageincludestwomaingearjustaftofcentergravityandaauxiliarygearnearthe．前三點(diǎn)起落架，由兩支在重心后的主輪，與一個(gè)在機(jī)頭的輔助前輪組成。（意譯）Themainadvantageoflayoutisthatiteliminatesthegroundproblemoftaildragger．4/前三點(diǎn)起落架最大的優(yōu)點(diǎn)是不會(huì)像后三點(diǎn)那樣，著陸時(shí)容易打轉(zhuǎn)。Thisarrangementisinsteadastablebecauseofthelocationofthemaingearwithrespecttothecenterofgravity．這得益于主輪子在重心后部的設(shè)計(jì)。Asaresultahasmoretolandsafelyevenwhenisnotwiththerunway．這樣，就算著陸時(shí)飛機(jī)沒(méi)有對(duì)準(zhǔn)跑道，飛行員還是有辦法修正方向的。前三點(diǎn)起落架Furthermorethetricyclearrangementisgenerallylessdemandingonthepilotandiseasiertotaxiandsteer．前三點(diǎn)起落架更容易操縱。（意譯）Thetricyclegearalsooffersmuchbetteroverthenosewellasalevelcabinfloortoeasepassengerandcargohandling．水平的機(jī)身，使視界比較好，而且便于裝貨及乘客行走。Afurtherplusisthattheaircraftataangleofattacksothatthethrustoftheengineismoretothedirectionofallowingfasteraccelerationduring．機(jī)翼的小迎角，螺旋槳在水平方向產(chǎn)生的力，有助于飛機(jī)更快獲得速度。（意譯）In，thenosewheelmakesitimpossibleforplanetotipoveronitsnoseduringlandingascansometimeshappenon．另外，由于前輪距重心較遠(yuǎn)，就不會(huì)出現(xiàn)后三點(diǎn)起落架容易發(fā)生的“拿大頂”現(xiàn)象。（意譯）5/Thegreatestdrawbacktricyclegearisthegreaterweightdragincurredbyaddingthelargenosewheelstrut．前三點(diǎn)起落架最大的缺點(diǎn)是，較重的重量及較大的阻力。（意譯）Whereasmanytaildraggerscanaffordtononretractinggearwithminimalimpactonperformance，withnosewheelsalmostalwaysrequireretractionmechanismstoreducedrag．另一方面固定式后三點(diǎn)起落架耐沖擊性能較強(qiáng)前三點(diǎn)起落架要收放式以減小飛行時(shí)的阻力。Someplaneswithtricyclealsohaverotatingthenoseupduringtakeoffbecausethemainwheelsarelocatedsoclosetothe，andtheremaybeinsufficientcontroleffectiveness．Similarly，theclosenesstotherudderreducesitseffectivenesscounteractingcrosswinds．前三點(diǎn)起落架影響舵效。（意譯）Anothercriticalfactorwhendesigningtricyclegearistoproperlybalancetheloadcarriedbythemaingearversusnosewheel．ToolittleloadonthemainwheelsreducestheirbrakingeffectivenesswhiletoolittleonthenosewheelreducesitssteeringeffectivenessCarefulbalancingofweightisalsoimportantpreventplanefromtippingbackonitstailwhileatrestontheground前三點(diǎn)起落架對(duì)飛機(jī)重心的要求也比較高。747加油次序不當(dāng)，造機(jī)尾觸地危險(xiǎn)。Therearemanyexamplesofaircraftwithtricyclelanding，includingthe－16andCessna172．F16與Cessna172都是前三點(diǎn)起落架的經(jīng)典案例。Summary6/總結(jié)Landinggearservesthreeprimarypurposes起落架的三個(gè)主要任務(wù)：toprovideasupportfortheplanewhenatrestontheground，一、把飛機(jī)停放在地面。toprovideastablechassisfortaxiingorrollingduringtakeoffandlanding，二、起飛及著陸時(shí)提供穩(wěn)定的支持。andtoprovideshockabsorbingsystemduringlanding．三、著陸時(shí)減震。Regardless，allofthesetasksaresecondarytotheplane’sprimaryroleasanefficientmodeoftravelthroughtheair飛機(jī)的飛行性能還是很重要的。（意譯）Toaircraftdesigners，landinggeararenothingmorethananecessaryevilsinceplanesaredesignedprimarilyforperformanceinflightratherthanonground飛機(jī)的飛行性能比在地面的性能重要的多。（意譯）TherehaveevenbeenattemptsoveryearstoeliminatelandinggearentirelyThemostextremewasstudybytheRoyalNavytoseeifajetcouldmakeabellylandingonthedeckofanaircraftcarriercoatedarubberizedsurface．有人嘗試過(guò)不使用起落架，直接用機(jī)腹在航母甲板上著陸。（意譯）Ifsuccessful，themethodwouldeliminatetheneedfortheverystrongandheavylandinggearusedonbasedaircraft．Unfortunately，