《直升機(jī)空氣動(dòng)力學(xué)與飛行原理》課件-模塊九：直升機(jī)特殊飛行（雙語(yǔ)）

模塊九：直升機(jī)特殊飛行Learnabouthelicopter

specialflight直升機(jī)空氣動(dòng)力學(xué)與飛行原理Helicopteraerodynamicsandprinciplesofflight模塊九：直升機(jī)特殊飛行Learnabouthelicopterspecialflight任務(wù)一：理解直升機(jī)自轉(zhuǎn)狀態(tài)Understandhelicopterself-rotatingstatus直升機(jī)空氣動(dòng)力學(xué)與飛行原理Helicopteraerodynamicsandprinciplesofflight活動(dòng)1：什么是直升機(jī)自轉(zhuǎn)狀態(tài)？01.PARTONEWhatisahelicopterself-rotatingstatus？活動(dòng)1：什么是直升機(jī)自轉(zhuǎn)狀態(tài)？自轉(zhuǎn)狀態(tài)屬于無(wú)動(dòng)力飛行，是直升機(jī)所特有的空氣動(dòng)力學(xué)現(xiàn)象，也是關(guān)系飛行安全的重要問(wèn)題。Self-rotating,belongingtounpoweredflight,isacharacteristicaerodynamicphenomenonofhelicoptersandanimportantissueconcerningflightsafety.活動(dòng)1：什么是直升機(jī)自轉(zhuǎn)狀態(tài)？當(dāng)發(fā)動(dòng)機(jī)失效或人為停車(chē)，在下降過(guò)程中必須有其它力來(lái)維持旋翼轉(zhuǎn)速保持直升機(jī)飛行直至著陸，可以由流過(guò)旋翼的氣流提供能量，以克服槳葉阻力讓旋翼旋轉(zhuǎn)，這個(gè)過(guò)程就是自轉(zhuǎn)。Whentheenginefailsorisstoppedartificially,otherforcesmustbepresentduringdescenttomaintainrotorspeedtokeepthehelicopterflyinguntillanding,whichcanbepoweredbyairflowthroughtherotortoovercomebladedragtospintherotor,aprocessknownasself-rotating.活動(dòng)1：什么是直升機(jī)旋翼失速？中國(guó)傳統(tǒng)的民間兒童玩具竹蜻蜓，凝結(jié)了中國(guó)古代智慧的結(jié)晶，能在空中對(duì)抗風(fēng)力而產(chǎn)生自旋，這種現(xiàn)象叫風(fēng)車(chē)狀態(tài)，其原理與直升機(jī)類似。Chinesetraditionalfolkchildren'stoysbamboodragonflies,condensedthecrystallizationofancientChinesewisdom,canbeintheairagainstthewindandproducespin,thisphenomenoniscalledwindmillstate,theprincipleissimilartothehelicopter.活動(dòng)1：什么是直升機(jī)旋翼失速？與竹蜻蜓不同的是，直升機(jī)利用旋翼原有的旋轉(zhuǎn)動(dòng)能和直升機(jī)的勢(shì)能，操縱直升機(jī)進(jìn)入自轉(zhuǎn)狀態(tài)且垂直下降率達(dá)到規(guī)定值，這種現(xiàn)象叫旋翼的自轉(zhuǎn)下降。Unlikethebamboodragonfly,thehelicopterutilizestherotor'soriginalrotationalkineticenergyandthehelicopter'spotentialenergytomaneuverthehelicopterintoastateofself-rotationandtheverticalrateofdescentreachesaspecifiedvalue,aphenomenoncalledrotor'sself-rotationdescent.活動(dòng)1：什么是直升機(jī)旋翼失速？自轉(zhuǎn)下降與竹蜻蜓的風(fēng)車(chē)狀態(tài)類似，但風(fēng)車(chē)狀態(tài)大多指的是產(chǎn)生扭矩，而自轉(zhuǎn)下降強(qiáng)調(diào)的是產(chǎn)生拉力。Thespindownissimilartothewindmillstateofthebamboodragonfly,butwhilethewindmillstatemostlyreferstothegenerationoftorque,thespindownemphasizesthegenerationoftension.活動(dòng)2：直升機(jī)自轉(zhuǎn)狀態(tài)的應(yīng)用場(chǎng)景？02.PARTTWOWhatistheapplicationofhelicopterself-rotatingstatus?活動(dòng)2：直升機(jī)自轉(zhuǎn)狀態(tài)的應(yīng)用場(chǎng)景？直升機(jī)在合適的時(shí)機(jī)進(jìn)入自轉(zhuǎn)狀態(tài)可以有效避免人員財(cái)產(chǎn)損失，下列情況直升機(jī)應(yīng)做自轉(zhuǎn)下降：Helicopterscaneffectivelyavoidlossofpersonnelandpropertybygoingintoself-rotatingattherighttime.Helicoptersshoulddoanself-rotatingdescentinthefollowingsituations:活動(dòng)2：直升機(jī)自轉(zhuǎn)狀態(tài)的應(yīng)用場(chǎng)景？發(fā)動(dòng)機(jī)發(fā)生故障，如空中停車(chē)或因發(fā)動(dòng)機(jī)振動(dòng)太大而被迫關(guān)車(chē)，駕駛員應(yīng)以自轉(zhuǎn)飛行方式來(lái)尋找迫降地點(diǎn)。Intheeventofanenginefailure,suchasanin-flightstoporforcedshutdownduetotoomuchenginevibration,thepilotshouldautorotatetofindacrashlandingsite.尾槳由于某種原因失效，不能平衡反扭矩時(shí)，為了安全著陸，駕駛員應(yīng)關(guān)閉發(fā)動(dòng)機(jī)，進(jìn)入自轉(zhuǎn)飛行并著陸。ThetailrotorfailedforsomereasonandcouldnotbalancethecountertorqueAtthispoint,inordertolandsafely,thepilotshouldshutdowntheengine,enterself-rotatingandland.活動(dòng)2：直升機(jī)自轉(zhuǎn)狀態(tài)的應(yīng)用場(chǎng)景？活動(dòng)2：直升機(jī)自轉(zhuǎn)狀態(tài)的應(yīng)用場(chǎng)景？直升機(jī)需陡降，為快速下降高度而不致陷入渦環(huán)狀態(tài)。Helicoptersarerequiredtomakeasteepdescentinordertomakearapiddescenttoaltitudewithoutgettingcaughtinavortexring.活動(dòng)2：直升機(jī)自轉(zhuǎn)狀態(tài)的應(yīng)用場(chǎng)景？在發(fā)動(dòng)機(jī)失效的初始瞬間，飛行員必須立即將總距桿放到最低槳距位置，否則的話，主槳轉(zhuǎn)速將迅速減小而引起槳葉錐體角迅速增大，槳葉快速向上揮舞。Attheinitialmomentofenginefailure,thepilotmustimmediatelyputthetotalpitchlevertothelowestpitchposition;otherwise,themainpropellerspeedwilldecreaserapidlycausingarapidincreaseinthebladeconeangleandarapidupwardswingoftheblade.活動(dòng)2：直升機(jī)自轉(zhuǎn)狀態(tài)的應(yīng)用場(chǎng)景？這是因?yàn)楣β适ズ鬅o(wú)法克服槳葉的型阻，大槳葉角會(huì)使阻力較大，旋翼轉(zhuǎn)速會(huì)迅速下降。Thisisbecausethelossofpowercannotovercomethetyperesistanceofthepaddles,andalargepaddleanglewillresultinalargerresistanceandarapiddecreaseinrotorspeed.活動(dòng)2：直升機(jī)自轉(zhuǎn)狀態(tài)的應(yīng)用場(chǎng)景？隨著旋翼轉(zhuǎn)速的迅速減小，離心力將無(wú)法再保持住理想的錐體角，錐體角將迅速增大，造成槳葉根部應(yīng)力迅速增大而引起槳葉大梁彎曲甚至完全折斷。Astherotorspeeddecreasesrapidly,thecentrifugalforcewillnolongerbeabletoholdtheidealconeangle,andtheconeanglewillincreaserapidly,resultinginarapidincreaseinthestressattherootofthepaddleandcausingthepaddlebeamtobendorevenbreakcompletely.活動(dòng)2：直升機(jī)自轉(zhuǎn)狀態(tài)的應(yīng)用場(chǎng)景？在完全放低總距桿的同時(shí)，飛行員還必須松開(kāi)腳蹬，使尾槳距減小，同時(shí)操縱周期變距桿，保持約60kn的前飛速度。Whilefullyloweringthepitchstick,thepilotmustalsoreleasethefootpegstoreducethetailrotorpitch,andatthesametimemaneuverthecyclicpitchsticktomaintainaforwardspeedofapproximately60kn.活動(dòng)2：直升機(jī)自轉(zhuǎn)狀態(tài)的應(yīng)用場(chǎng)景？完成上述動(dòng)作后，直升機(jī)將進(jìn)入下降飛行通道且保持一定的前飛速度。Aftercompletingtheabovemaneuvers,thehelicopterwillenteradescendingflightpathandmaintainacertainforwardspeed.活動(dòng)3：直升機(jī)自轉(zhuǎn)下降時(shí)如何操縱？03.PARTTHREEHowtomaneuverahelicopterinaself-rotatingdescent？活動(dòng)3：直升機(jī)自轉(zhuǎn)下降時(shí)如何操縱？自轉(zhuǎn)下降分為三種形式:自轉(zhuǎn)下降到復(fù)飛自轉(zhuǎn)下降到著陸巡航中自轉(zhuǎn)下降Self-rotatingdescentisdividedintothreeforms:self-rotatingdescenttogoaroundself-rotatingdescenttolandingself-rotatingdescentincruiseNO1.Entry:Lowercollectivepitchstick,throttleofftoidlewhileyawcorrection,heightcorrectionwithstick;活動(dòng)3：直升機(jī)自轉(zhuǎn)下降時(shí)如何操縱？01.進(jìn)入:下放總距桿，關(guān)油門(mén)到慢車(chē)，同時(shí)修正偏航，帶桿修正高度;高空中自轉(zhuǎn)下降的操縱特點(diǎn)總結(jié)Thehandingcharacteristicsofself-rotatingdescentathighaltitudearesummarizedas:活動(dòng)3：直升機(jī)自轉(zhuǎn)下降時(shí)如何操縱？02.自轉(zhuǎn)下降中:檢查旋翼轉(zhuǎn)速、空速，保持協(xié)調(diào)飛行;高空中自轉(zhuǎn)下降的操縱特點(diǎn)總結(jié)03.復(fù)飛:打開(kāi)油門(mén)，上提總距桿，設(shè)定上升功率，直到到達(dá)上升高度。NO2.Inself-rotatingdescent:checkrotorrpm,airspeedandmaintaincoordinatedflight;NO3.Goaround:Openthethrottle,raisethecollectivepitchlever,andsettheascentpoweruntiltheascentaltitudeisreached.活動(dòng)3：直升機(jī)自轉(zhuǎn)下降時(shí)如何操縱？若直接著陸不進(jìn)行復(fù)飛，則在到達(dá)復(fù)飛高度時(shí)，繼續(xù)下降高度，在高度至6-3英尺時(shí)，根據(jù)下降快慢協(xié)調(diào)一致地上提總距桿，并向前頂桿，使滑撬與道面平行，用舵保持方向。接地后，把總距桿柔和地放到底。Ifadirectlandingdoesnotperformagoaround,continuethedescentatagoaroundaltitudeof,atanaltitudeof6–3feet,pullupthecollectivepitchstickinunisonwiththerateofdescent,andpushthestickforwardsothattheskidsareparalleltothepavement,withruddertomaintaindirection.Aftertouchdown,gentlylowerthecollectivepitchbartothebottom.活動(dòng)3：直升機(jī)自轉(zhuǎn)下降時(shí)如何操縱？巡航中自轉(zhuǎn)下降，可以根據(jù)選擇的著陸點(diǎn)進(jìn)行航程自轉(zhuǎn)下降Self-rotatingdescentincruise,withtheabilitytomakeavoyageself-rotatingdescentbasedontheselectedlandingsiteSummary總結(jié)任務(wù)二：理解直升機(jī)自轉(zhuǎn)狀態(tài)Understandhelicopterself-rotatingstatus01什么是直升機(jī)自轉(zhuǎn)狀態(tài)？Whatisahelicopterself-rotatingstatus?02直升機(jī)自轉(zhuǎn)狀態(tài)的應(yīng)用場(chǎng)景？Whatistheapplicationofhelicopterself-rotatingstatus?03直升機(jī)自轉(zhuǎn)下降時(shí)如何操縱？Howtomaneuverahelicopterinaself-rotatingdescent？Thinking思考回憶童年，體驗(yàn)竹蜻蜓的飛行姿態(tài)，對(duì)比直升機(jī)自轉(zhuǎn)下降和風(fēng)車(chē)狀態(tài)的區(qū)別？模塊九：直升機(jī)特殊飛行Learnabouthelicopterspecialflight任務(wù)二：理解直升機(jī)渦環(huán)狀態(tài)Understandhelicoptervortexringstatus直升機(jī)空氣動(dòng)力學(xué)與飛行原理Helicopteraerodynamicsandprinciplesofflight活動(dòng)1：什么是直升機(jī)渦環(huán)狀態(tài)？01.PARTONEWhatisahelicoptervortexringstatus？活動(dòng)1：什么是直升機(jī)渦環(huán)狀態(tài)？直升機(jī)作垂直下降或以小空速飛行時(shí)，如果下降率較大，向上氣流會(huì)阻礙滑流運(yùn)動(dòng)，其中一部分空氣重新吸入旋翼中的現(xiàn)象，稱為渦環(huán)狀態(tài)。Whenahelicopterisdescendingverticallyorflyingatlowairspeeds,iftherateofdescentishigh,theupwardflowobstructstheslipstreammotion,withsomeoftheairreingestingintotherotor,aphenomenoncalledvortexringcondition.活動(dòng)1：什么是直升機(jī)渦環(huán)狀態(tài)？直升機(jī)處在渦環(huán)狀態(tài)中飛行，此時(shí)發(fā)動(dòng)機(jī)仍然處在工作中，即使飛行員采用發(fā)動(dòng)機(jī)全功率，直升機(jī)仍然保持下沉，所以也可以采用“大功率下沉”這個(gè)術(shù)語(yǔ)來(lái)描述這種特殊飛行狀態(tài)。Thehelicopterisflyinginthevortexringstate,whentheengineisstillinoperation,evenifthepilotusesthefullpoweroftheengine,thehelicopterisstillsinking,sotheterm"highpowersinking"canalsobeusedtodescribethisspecialflightstate.活動(dòng)1：什么是直升機(jī)渦環(huán)狀態(tài)？直升機(jī)下降中，旋翼上面吸入的空氣與自下而上的相對(duì)氣流流相遇，在壓力差作用下，有少部分空氣從旋翼下面自下而上地向旋翼上面低壓區(qū)流動(dòng)。經(jīng)過(guò)多次循環(huán)，就形成了槳尖渦流。Whenthehelicopterisdescending,theairinhaledabovetherotormeetstherelativeairflowflowfromthebottomup,andasmallportionoftheairflowsfrombelowtherotortothelow-pressureareaabovetherotorfromthebottomupunderthepressuredifference.Aftermanycycles,thetipvortexisformed.活動(dòng)1：什么是直升機(jī)渦環(huán)狀態(tài)？槳尖渦流是形成渦環(huán)狀態(tài)的內(nèi)因，而直升機(jī)的垂直下降則是形成渦環(huán)狀態(tài)的外因。Thepaddletipvorticesaretheinternalcauseoftheformationofthevortexringstate,whiletheverticaldescentofthehelicopteristheexternalcauseoftheformationofthevortexringstatus.活動(dòng)1：什么是直升機(jī)渦環(huán)狀態(tài)？尾槳也會(huì)形成渦環(huán)狀態(tài)，兩者形成的原因相似。直升機(jī)尾槳渦環(huán)形成與偏轉(zhuǎn)角速度有關(guān)，直升機(jī)向某一方向懸停轉(zhuǎn)彎角速度過(guò)快時(shí)，尾槳也可能陷入渦環(huán)狀態(tài)。Thetailrotorcanalsoformavortexring,andthereasonsfortheirformationaresimilar.Helicoptertailrotorvortexringformationanddeflectionangularvelocity,helicopterhoveringinacertaindirectionturningangularvelocityistoofast,thetailrotormayalsofallintothevortexringstate.活動(dòng)1：什么是直升機(jī)渦環(huán)狀態(tài)？渦環(huán)狀態(tài)出現(xiàn)后，將會(huì)造成氣流分離、低頻振動(dòng)、產(chǎn)生額外噪音以及升力減小等現(xiàn)象，旋翼產(chǎn)生的拉力減小，下降率增大。下降率越大，渦環(huán)現(xiàn)象越嚴(yán)重，旋翼拉力減小越多。Afterthevortexringstateoccurs,itwillcauseflowseparation,low-frequencyvibration,additionalnoisegeneration,andreducedlift,reducingthepullgeneratedbytherotorandincreasingtherateofdescent.Thegreatertherateofdescent,themoreseverethevortexringphenomenonandthemorereducedtherotorpull.旋翼拉力忽大忽小，引起旋翼和直升機(jī)發(fā)生抖動(dòng)，搖晃現(xiàn)象，操縱性變差，嚴(yán)重時(shí)可能造成操縱失效。Rotorpullvaries,causingtherotorandhelicoptertoshake,shake,andpoorhandling,whichcancausecontrolfailureinseverecases.活動(dòng)1：什么是直升機(jī)渦環(huán)狀態(tài)？活動(dòng)1：什么是直升機(jī)渦環(huán)狀態(tài)？渦環(huán)狀態(tài)造成的振動(dòng)極易使得旋翼產(chǎn)生疲勞強(qiáng)度破壞，如裂紋、斷裂等，因此在進(jìn)行維護(hù)工作時(shí)，要保持良好的維護(hù)作風(fēng)和工作規(guī)范，對(duì)工作認(rèn)真負(fù)責(zé)。Thevibrationcausedbythevortexringstateisveryeasytomaketherotorproducefatigue

strengthdamage,suchascracks,fractures,etc.Therefore,whencarryingoutmaintenancework,weshouldmaintainagoodmaintenancestyleandworknorms,andbeconscientiousandresponsibleforthework.活動(dòng)2：渦環(huán)狀態(tài)的形成場(chǎng)景02.PARTTWOScenesoftheformationofvortexringstatus活動(dòng)2：渦環(huán)狀態(tài)的形成場(chǎng)景當(dāng)直升機(jī)發(fā)動(dòng)機(jī)正常工作，且直升機(jī)處于懸停狀態(tài)（Vy=0），不會(huì)形成渦環(huán)，只形成少量槳尖渦流(如圖A所示）。Whenthehelicopterengineisworkingproperlyandthehelicopterisinhover(Vy=0),novortexringsform,onlyasmallnumberoftipvorticesform(asshowninfigureA).活動(dòng)2：渦環(huán)狀態(tài)的形成場(chǎng)景當(dāng)直升機(jī)發(fā)動(dòng)機(jī)正常工作，且直升機(jī)處于垂直下降狀態(tài)，形成少量渦環(huán)(如圖B所示）。Whenthehelicopterengineisworkingproperlyandthehelicopterisinaverticaldescent,asmallnumberofvortexform(asshowninfigureB).活動(dòng)2：渦環(huán)狀態(tài)的形成場(chǎng)景當(dāng)直升機(jī)發(fā)動(dòng)機(jī)正常工作，且直升機(jī)垂直下降速度較快，會(huì)形成強(qiáng)烈的渦環(huán)(如圖C所示）。Whenthehelicopterengineisworkingproperlyandthehelicopterisdescendingverticallyfaster,strongvortexringsform(asshowninfigureC).活動(dòng)2：渦環(huán)狀態(tài)的形成場(chǎng)景當(dāng)直升機(jī)發(fā)動(dòng)機(jī)正常工作，且直升機(jī)垂直下降速度更快，向上的氣流會(huì)吹掉渦環(huán)(如圖D所示），進(jìn)入旋翼自轉(zhuǎn)。Whenthehelicopterengineisworkingproperlyandthehelicopterisdescendingverticallyfaster,theuowardsirflowblowsawaythevortexring(asshowninfigureD)intorotorrotation.活動(dòng)3：如何預(yù)防或改出渦環(huán)狀態(tài)？03.PARTTHREEHowtopreventorchangeoutofvortexringstatus?活動(dòng)3：如何預(yù)防或改出渦環(huán)狀態(tài)？01.如無(wú)特殊需要，特別是高度在10～200m時(shí)，不要做垂直下降，宜做帶空速的下降。（一）要防止進(jìn)入渦環(huán)狀態(tài)，飛行中應(yīng)注意如下幾點(diǎn)Toprevententeringthevortexringstate,thefollowingpointsshouldbenotedduringflight:(1)Ifthereisnospecialneed,especiallywhentheheightis10~200m,donotdoverticaldescent,itisadvisabletododescentwithairspeed.活動(dòng)3：如何預(yù)防或改出渦環(huán)狀態(tài)？02.做垂直下降或小速度下降時(shí)，下降率不要太大。（一）要防止進(jìn)入渦環(huán)狀態(tài)，飛行中應(yīng)注意如下幾點(diǎn)03.在剩余功率較小的情況下(如載重大、海拔高度高或氣溫高等)，不要勉強(qiáng)做懸?；虼怪鄙仙?。(2)Whendoingverticaldescentorsmallspeeddescent,thedescentrateshouldnotbetoobig.(3)Inthecaseofsmallresidualpower(suchaslargeload,highaltitudeorhightemperature),don'tbereluctanttodohoveringorverticalrise.活動(dòng)3：如何預(yù)防或改出渦環(huán)狀態(tài)？改出渦環(huán)狀態(tài)的一般作法就是操縱總距桿。如果發(fā)現(xiàn)直升機(jī)垂直下降率增大，是由于發(fā)動(dòng)機(jī)功率不足引起的，則應(yīng)及時(shí)地上提總距桿，迅速增大發(fā)動(dòng)機(jī)功率，以制止下降率繼續(xù)增大。Ifitisfoundthatthehelicopterverticalrateofdescentincreasesduetoinsufficientenginepower,thecollectivepitchbarshouldberaisedintimetorapidlyincreaseenginepowertostoptherateofdescentfromcontinuingtoincrease.活動(dòng)3：如何預(yù)防或改出渦環(huán)狀態(tài)？如果上提總距桿也不能制止下降率繼續(xù)增大，在一定的高度以上則應(yīng)迅速地前推駕駛桿，使直升機(jī)產(chǎn)生前飛速度，把渦環(huán)吹掉，脫離渦環(huán)狀態(tài)。Ifraisingthecollectivepitchbardoesnotstopthedescentratefromcontinuingtoincrease,pushthestickforwardquicklyaboveacertainaltitudetoallowthehelicoptertodevelopforwardflightspeed,blowingthevortexringoffandoutofthevortexringcondition.活動(dòng)3：如何預(yù)防或改出渦環(huán)狀態(tài)？在操縱駕駛桿沒(méi)有異常感覺(jué)時(shí)這種措施對(duì)改出渦環(huán)最為有效，損失高度的較少。Thismeasureismosteffectiveinrecoveringthevortexringwhenthereisnounusualfeelfromthecontrolstick,withlesslossofaltitude.活動(dòng)3：如何預(yù)防或改出渦環(huán)狀態(tài)？如果操縱效能已降低或失效，推桿也無(wú)法增大前飛速度，則應(yīng)迅速地下放總距桿，增大下降率，使自下而上的相對(duì)氣流速度增大，把繞著旋翼轉(zhuǎn)動(dòng)的環(huán)流向旋翼上方吹掉。Ifthecontroleffectivenesshasbeenreducedordisabledandthestickcannotincreaseforwardflightspeed,thecollectivepitchstickshouldberapidlyloweredtoincreasetherateofdescentsothattherelativeairflowvelocityfrombottomtotopincreases,blowingthecirculationaroundtherotorupabovetherotor.活動(dòng)3：如何預(yù)防或改出渦環(huán)狀態(tài)？然后再推駕駛桿增大前飛速度，改出渦環(huán)狀態(tài)。這種方法損失高度較多，只有在高度較高或迫不得已時(shí)才采用。Thenpushthestickagaintoincreaseforwardflightspeed,changingoutofvortexringstatus.Thismethodlosesmuchaltitudeandisonlyusedwhenaltitudeishighornecessitated.Summary總結(jié)01什么是直升機(jī)渦環(huán)狀態(tài)？Whatisahelicoptervortexringstatus?任務(wù)三：理解直升機(jī)渦環(huán)狀態(tài)Understandhelicoptervortexringstatus02渦環(huán)狀態(tài)的形成場(chǎng)景Scenesoftheformationofvortexringstates03如何預(yù)防或改出渦環(huán)狀態(tài)？Howtopreventorchangeoutofvortexringstatus?Thinking思考尾槳渦環(huán)失效的原因與旋翼類似，思考并試著畫(huà)出尾槳失效的過(guò)程圖。模塊九：直升機(jī)特殊飛行Learnabouthelicopterspecialflight任務(wù)三：理解直升機(jī)尾槳失效Understandhelicoptertailrotoreffectiveness直升機(jī)空氣動(dòng)力學(xué)與飛行原理Helicopteraerodynamicsandprinciplesofflight活動(dòng)1：什么是直升機(jī)尾槳失效？01.PARTONEWhatisalossofhelicoptertailrotoreffectiveness?活動(dòng)1：什么是直升機(jī)尾槳失效？Tounderstandwhatisalossofhelicoptertailrotoreffectiveness,wemustfirstknowwhatthetailrotordoestothehelicopter.要了解什么是直升機(jī)的尾槳失效，我們就必須先要知道尾槳對(duì)直升機(jī)的作用?；顒?dòng)1：什么是直升機(jī)尾槳失效？Theoriginalhelicopterdesignshadonlyonerotatingmainrotorusedtoprovidelift,butinordertocontrolflightdirectionandstability,designersbeganexperimentingwithaddingdifferentformsoftailstabilizers.Theadventofthetailrotorsolvedthisproblem.最初的直升機(jī)設(shè)計(jì)中只有一個(gè)旋轉(zhuǎn)的主旋翼用來(lái)提供升力，但為了控制飛行方向和穩(wěn)定性，設(shè)計(jì)者開(kāi)始嘗試加裝不同形式的尾部穩(wěn)定器。尾槳的出現(xiàn)解決了這一問(wèn)題?；顒?dòng)1：什么是直升機(jī)尾槳失效？最早的尾槳通常是固定式的，位于直升機(jī)尾部，用來(lái)穩(wěn)定方向和維持平衡。后來(lái)，隨著直升機(jī)飛行速度的逐漸提高，固定式尾槳不能很好地滿足空氣動(dòng)力學(xué)需求。Theearliesttailrotorwasusuallyfixedandlocatedatthetailofthehelicoptertostabilizethedirectionandmaintainbalance.Later,asthehelicopter'sflightspeedgraduallyincreased,thefixedtailrotorcouldnotmeettheaerodynamicrequirementswell.活動(dòng)1：什么是直升機(jī)尾槳失效？因此可變尾槳應(yīng)運(yùn)而生。這種尾槳可以調(diào)節(jié)槳葉傾角，以保證在各種速度和飛行角度下，始終能夠提供足夠的穩(wěn)定性和操縱性。Thusthevariabletailrotorwasborn.Thistailrotoradjuststheinclinationofthebladestoensurethatadequatestabilityandmaneuverabilityarealwaysprovidedatallspeedsandflightangles.(1)Thepullingforce(orthrust)formedbythetailrotorformsadeflectionmomenttobalancethereactionmomentoftherotor.活動(dòng)1：什么是直升機(jī)尾槳失效？01.尾槳形成的拉力(或推力)形成偏轉(zhuǎn)力矩，用以平衡旋翼的反作用力矩。尾槳的作用Theroleofthetailrotorcanbesummarizedinthefollowingthreepoints:(2)Bychangingthetension(orthrust)ofthetailrotor,theyawcontrolofthehelicopterisachieved,andtherotatingtailrotoractsastheverticalstabilizerofthehelicopter,improvingitsdirectionalstability.活動(dòng)1：什么是直升機(jī)尾槳失效？02.通過(guò)變距改變尾槳的拉力(或推力)而實(shí)現(xiàn)直升機(jī)的偏航操縱，而且旋轉(zhuǎn)的尾槳相當(dāng)于直升機(jī)的垂直安定面，改善直升機(jī)的方向穩(wěn)定性。尾槳的作用Theroleofthetailrotorcanbesummarizedinthefollowingthreepoints:(3)Insomehelicopters,thetailrotorisinclinedupwardatanangletoprovidepartialliftandtoadjustthehelicopter'scenterofgravity.活動(dòng)1：什么是直升機(jī)尾槳失效？03.某些直升機(jī)的尾軸向上斜置一個(gè)角度，可以提供部分升力，也可以調(diào)節(jié)直升機(jī)的重心范圍。尾槳的作用Theroleofthetailrotorcanbesummarizedinthefollowingthreepoints:中國(guó)直-9直升機(jī)的“涵道風(fēng)扇”尾槳是中國(guó)自主設(shè)計(jì)和研發(fā)的尖端航空技術(shù)之一，優(yōu)點(diǎn)在于尾槳占用空間小，氣動(dòng)力效率高，尾槳不易為外物所傷。The"culvertfan"tailrotorofChina'sZ-9helicopterisoneofthecutting-edgeaeronauticaltechnologiesindependentlydesignedanddevelopedbyChina,withtheadvantagesthatthetailrotortakesuplittlespace,hashighaerodynamicefficiencyandisnoteasytobeinjuredbyexternalobjects.活動(dòng)1：什么是直升機(jī)尾槳失效？活動(dòng)1：什么是直升機(jī)尾槳失效？而且由于涵道尾槳空氣阻力小，因此速度比普通直升機(jī)要快。是目前批量生產(chǎn)的飛行速度最快的直升機(jī)。Andbecausetheculverttailrotorhaslessairresistance,itisfasterthanordinaryhelicopters.Itisthefastestflyinghelicoptercurrentlyinmassproduction.活動(dòng)1：什么是直升機(jī)尾槳失效？作為中國(guó)第一種完全由自主設(shè)計(jì)和研發(fā)的直升機(jī)，直-9直升機(jī)已經(jīng)成為中國(guó)軍方和民用用戶的主力機(jī)型之一，這種尾槳不僅僅是技術(shù)上的突破，更體現(xiàn)了中國(guó)航空工業(yè)的成就和民族自豪感。TheZ-9helicopterhasbecomeoneofthemainmodelsfortheChinesemilitaryandcivilianusers.Thistailrotorisnotonlyatechnologicalbreakthrough,butalsoreflectstheachievementsofChina'saerospaceindustryandnationalpride.活動(dòng)1：什么是直升機(jī)尾槳失效？直升機(jī)尾槳失效，縮寫(xiě)為L(zhǎng)TE,也稱為喪失尾槳效應(yīng)，是近年來(lái)造成直升機(jī)失控事故的一個(gè)重要原因。Lossofhelicoptertailrotoreffectiveness,abbreviatedLTE,alsoknownaslossoftailrotoreffect,hasbeenamajorcauseofhelicopterloss-of-controlaccidentsinrecentyears.活動(dòng)1：什么是直升機(jī)尾槳失效？這是直升機(jī)在最后進(jìn)近著陸或貼近地面飛行時(shí)的低高度、低空速飛行狀態(tài)下發(fā)生的緊急情況，直升機(jī)會(huì)發(fā)生非指令的快速偏轉(zhuǎn)，并且不會(huì)自動(dòng)改出。Thisisanemergencysituationthatoccurswhenthehelicopterisinalowaltitude,lowairspeedflightstateonfinalapproachtolandingorflyingclosetotheground,wherethehelicopterundergoesanuncommanded,rapiddeflectionanddoesnotautomaticallychangeout.活動(dòng)1：什么是直升機(jī)尾槳失效？在多數(shù)情況下，飛行員不當(dāng)或較遲的修正措施可能加劇不可控制的偏轉(zhuǎn)，導(dǎo)致直升機(jī)失去控制。所以，飛行員必須能預(yù)見(jiàn)尾槳失效并及時(shí)改出。Inmostcases,improperorlatecorrectiveactionbythepilotcanexacerbateuncontrollabledeflectionsandresultinlossofcontrolofthehelicopter.Therefore,pilotsmustbeabletoanticipatetailrotorfailureandchangeoutinatimelymanner.活動(dòng)1：什么是直升機(jī)尾槳失效？尾槳失效現(xiàn)象與直升機(jī)的機(jī)械系統(tǒng)沒(méi)有聯(lián)系，旋翼旋轉(zhuǎn)時(shí)產(chǎn)生的槳尖渦流以及自然風(fēng)都會(huì)對(duì)尾槳拉力產(chǎn)生影響，尾槳不能提供適當(dāng)?shù)睦Ρ３趾较?。Thephenomenonoftailrotorfailureisnotlinkedtothemechanicalsystemofthehelicopter;therotortipvorticesgeneratedbytherotorrotationaswellasthenaturalwindshaveaneffectonthetailrotorpull,andthetailrotorisnotabletoprovidetheproperpulltomaintaintheheading.活動(dòng)1：什么是直升機(jī)尾槳失效？所有單旋翼帶尾槳直升機(jī)在懸停時(shí)受到風(fēng)的影響，或高高度小速度飛行情況下都有可能發(fā)生尾槳失效現(xiàn)象。Allsingle-rotorhelicopterswithtailrotoraresubjecttotailrotorfailurewhenhoveringundertheinfluenceofwind,orwhenflyingathighaltitudesandlowspeeds.活動(dòng)2：什么情況下可能會(huì)發(fā)生LTE？02.PARTTWOWhenisLTElikelytooccur?活動(dòng)2：什么情況下可能會(huì)發(fā)生LTE？大量的飛行和風(fēng)洞試驗(yàn)表明，有3種相對(duì)風(fēng)結(jié)合直升機(jī)特性單獨(dú)或綜合作用，可能會(huì)使直升機(jī)產(chǎn)生LTE現(xiàn)象。Numerousflightandwindtunneltestshaveshownthattherearethreetypesofrelativewindscombinedwithhelicoptercharacteristicsthat,aloneorincombination,maycausethehelicoptertoproduceLTEphenomena.活動(dòng)2：什么情況下可能會(huì)發(fā)生LTE？Thewindisblowingfromtheleftfront,blowingtherotorbladetipvortexintothetailrotor,makingthetailrotorworkinanextremelyturbulentenvironment.Atthispoint,therelativewindiswithintherotorbladetipinterferencezone.（一）風(fēng)從左前方吹來(lái)，將旋翼槳尖渦吹進(jìn)尾槳，使尾槳工作在極度的紊流環(huán)境中。此時(shí)，相對(duì)風(fēng)處在旋翼槳尖干擾區(qū)內(nèi)。右旋旋翼直升機(jī)右轉(zhuǎn)彎時(shí)，為了保持固定的轉(zhuǎn)彎角速度，應(yīng)該蹬右舵減小尾槳拉力，以保持相同的偏轉(zhuǎn)速率。Whenarightrotorhelicopterturnsright,inordertomaintainafixedangularrateofturn,therightruddershouldbestrokedtoreducethetailrotorpullinordertomaintainthesamerateofdeflection.活動(dòng)2：什么情況下可能會(huì)發(fā)生LTE？活動(dòng)2：什么情況下可能會(huì)發(fā)生LTE？當(dāng)旋翼槳尖渦通過(guò)尾槳時(shí)，尾槳進(jìn)入旋翼槳尖渦干擾區(qū)域，尾槳槳葉迎角減小，導(dǎo)致尾槳拉力減小，直升機(jī)將加速右轉(zhuǎn)。Astherotorbladetipvortexpassesoverthetailrotor,thetailrotorenterstherotorbladevortexinterferenceregionandthetailrotorbladeangleofapproachdecreases,resultinginadecreaseintailrotorpullandthehelicopterwillaccelerateintoarightturn.活動(dòng)2：什么情況下可能會(huì)發(fā)生LTE？尾槳拉力的減小是突然發(fā)生的，如果不及時(shí)修正，會(huì)發(fā)展成為不可控制的繞軸快速旋轉(zhuǎn)，最終導(dǎo)致LTE。Thereductionintailrotorpulloccurssuddenlyand,ifnotcorrectedintime,candevelopintoanuncontrollablerapidrotationaroundtheshaft,eventuallyleadingtoLTE.活動(dòng)2：什么情況下可能會(huì)發(fā)生LTE？Whentherelativewindisinthewindvaneeffectzone,therelativewindwillcausethehelicoptertowindvane,thenosewillturntothewindwarddirection,andifnocorrectionismade,thehelicopterwillautomaticallyrotateslowly,thedirectionofwhichdependsonthewinddirection.（二）當(dāng)相對(duì)風(fēng)處在風(fēng)標(biāo)效應(yīng)區(qū)內(nèi)，相對(duì)風(fēng)會(huì)使直升機(jī)產(chǎn)生風(fēng)標(biāo)效應(yīng)，機(jī)頭將轉(zhuǎn)向迎風(fēng)方向，如果不進(jìn)行修正，直升機(jī)將會(huì)自動(dòng)緩慢地旋轉(zhuǎn)，其方向取決于風(fēng)向。活動(dòng)2：什么情況下可能會(huì)發(fā)生LTE？如果飛行員允許直升機(jī)以一定的角速度旋轉(zhuǎn)，尾部進(jìn)入此區(qū)域，則偏航角速度會(huì)突然增加。Ifthepilotallowsthehelicoptertorotateatacertainangularvelocitywiththetailenteringthisarea,theyawangularvelocitywillsuddenlyincrease.為了防止直升機(jī)在這種順風(fēng)時(shí)發(fā)生LTE,飛行時(shí)必須密切注意直升機(jī)的狀態(tài)，主動(dòng)控制偏轉(zhuǎn)速率，并集中注意力駕駛直升機(jī)。

TopreventthehelicopterfromLTEinthisdownwind,itisimportanttoflythehelicopterwithcloseattentiontothehelicopter'scondition,activelycontroltheyawrate,andconcentrateonflyingthehelicopter.活動(dòng)2：什么情況下可能會(huì)發(fā)生LTE？活動(dòng)2：什么情況下可能會(huì)發(fā)生LTE？Ifthewindisblowingfrom210°~330°,thewindwillcausethetailrotortoproduceavortexringstate.Atthistime,thetailrotorisinachangingandunstableflowfield,causingthetailrotorpullingforcetooscillate.（三）如