EnglishforUnmannedaerialvehicle無人機專業(yè)英語Project4:FlightDynamicsofUAV-------Fixed-wingdroneAerodynamicforcesControlsurfacesAileronsElevatorsRudderFlapsswivel [?sw?vl]vt.（使）旋轉(zhuǎn);在樞軸上轉(zhuǎn)動perpendicular[?p?:p?n?d?kj?l?(r)]adj.垂直的，成直角的sideslip['sa?dsl?p]n.側(cè)滑profile [?pr??fa?l]n.側(cè)面;外形，輪廓airfoil [?e?f??l]n.翼面deflect [d??flekt]vt.使彎曲;偏轉(zhuǎn)camber [?k?mb?(r)]n.拱形versatile[?v?:s?ta?l]adj.多功能的;多用途的hinge[h?nd?]n.鉸鏈NewWordsswash[sw??]platen.傾斜盤gearbox [?g??b?ks]n.變速箱;齒輪箱;變速器collectivepitch[k??lektivpit?]n.總距rod[r?d]n.桿，拉桿cyclicpitch[?sa?kl?kpit?]n.周期槳距bearing [?be?r??]n.軸承NewWordsFlightdynamicsofUAVreferstothestudyoftheperformance,stability,andcontrolofunmannedaerialvehicles.Itisconcernedwithhowforcesactingonthevehicleinfluenceitsspeedandattitudewithrespecttotime.無人機飛行動力學研究的是無人機的性能、穩(wěn)定性和控制。它關心的是作用在無人機上的力如何影響其速度和姿態(tài)。Part0----WhatisFlightDynamicsThethreecriticalflightdynamicsparametersoffixed-wingdronearetheanglesofrotationinthreedimensionsaboutthevehicle‘scenterofmass,knownaspitch,rollandyaw.固定翼無人機三個關鍵的飛行動力參數(shù)是以飛機重心為坐標原點的三維坐標系下的旋轉(zhuǎn)角，即我們熟知的俯仰角、橫滾角和偏航角。Themostcommonaeronauticalconventiondefinestherollasactingaboutthelongitudinalaxis,positivewiththestarboard(right)wingdown.Theyawisabouttheverticalbodyaxis,positivewiththenosetostarboard.Pitchisaboutanaxisperpendiculartothelongitudinalplaneofsymmetry,positivenoseup.最通常的航空慣例定義橫滾軸為飛機的縱軸，向右滾轉(zhuǎn)為正方向；偏航軸為飛機立軸，向右偏航為正；俯仰軸垂直于飛機縱向?qū)ΨQ面，飛機抬頭為正。Part1----Fixed-wingdroneAfixed-wingdroneincreasesordecreasestheliftgeneratedbythewingswhenitpitchesnoseupordownbyincreasingordecreasingtheangleofattack(AOA).Therollangleisalsoknownasbankangleonafixed-wingaircraft,whichusually"banks"tochangethehorizontaldirectionofflight.Anaircraftisusuallystreamlinedfromnosetotailtoreducedragmakingittypicallyadvantageoustokeepthesideslipanglenearzero.當飛機俯仰時，其攻角會增加或者減少，帶來的是通過機翼產(chǎn)生的升力的增加或者減少。橫滾角也叫傾斜角，一般是通過傾斜來改變飛行的水平方向。飛機從機頭到機尾通常呈流線型，這樣可以減少阻力，通常有利于保持側(cè)滑角接近于零。Part1----Fixed-wingdroneEssentiallythereare4aerodynamicforcesthatactonanairplaneinflight;thesearelift,drag,thrustandweight.飛機在飛行中主要受到4個力：升力、阻力、推理和重力。Part2----AerodynamicforcesInsimpleterms,dragistheresistanceofairmoleculeshittingtheairplane(thebackwardforce),thrustisthepoweroftheairplane'sengine(theforwardforce),liftistheupwardforceandweightisthedownwardforce.So,forairplanestoflyandstayairborne,thethrustmustbegreaterthanthedragandtheliftmustbegreaterthantheweight.簡單來說，阻力是空氣分子撞擊飛機產(chǎn)生的阻滯力；推力是飛機發(fā)動機的動力；升力是向上的力；重力是向下的力。因此，飛機要飛起來并維持飛行狀態(tài)，推力必須大于阻力，并且升力必須大于重力。Acrosssectionofatypicalairplanewingshowthetopsurfacetobemorecurvedthanthebottomsurface.Thisshapedprofileiscalledan'airfoil'andtheshapeexistsbecauseit'slongbeenproven(sincethedawnofflight)thatanairfoilgeneratessignificantlymoreliftthanopposingdrag.典型飛機機翼的橫截面是上表面比底部更彎曲。這種形狀的翼型稱作一種翼面，而且已經(jīng)證明了這種形狀的機翼產(chǎn)生的升力比飛行阻力要多得多。Part2----AerodynamicforcesDuringflight,airnaturallyflowsoverandbeneaththewingandisdeflectedupwardsoverthetopsurfaceanddownwardsbeneaththelowersurface.Anydifferenceindeflectioncausesadifferenceinairpressure('pressuregradient')andbecauseoftheairfoilshapethepressureofthedeflectedairislowerabovetheairfoilthanbelowit.Asaresult,thewingis'pushed'upwardsbythehigherpressurebeneath.在飛行中，空氣自然地流過機翼上下表面，并且沿著上下表面彎曲。彎曲上的任何改變會引起空氣壓力的改變，并且由于翼面形狀特性，翼面上表面空氣壓力比下表面低。結(jié)果是，機翼被下表面高壓空氣向上托起。Part2----AerodynamicforcesLocatedonthetrailingedge(rear)ofthewing,theaileronscontroltheairplane‘srollaboutitslongitudinalaxis.Eachaileronmovesatthesametimebutinoppositedirectionsi.e.whentheleftaileronmovesup,therightaileronmovesdownandviceversa.位于機翼的后緣，副翼控制飛機沿飛機縱軸滾轉(zhuǎn)的動作。每一個同時動作，但是轉(zhuǎn)動方向相反，例如，當左副翼朝上，則右副翼朝下，反之亦然。Part3----AileronsThismovementcausesaslightdecreaseinliftonthewingtipwiththeupwardmovingaileron,whiletheoppositewingtipexperiencesaslightincreaseinlift.Becauseofthesesubtlechangesinlift,theairplaneisforcedtorollintheappropriatedirectioni.e.whentheoperatormovesthecontrolsticktotheleftonthetransmitter,theleftaileronwillriseandtheairplanewillrollleftinresponsetothechangeinliftoneachwing.向上的副翼會引起翼梢上升力的輕微減少，與之相對的翼梢上的升力則略微增加。由于升力的輕微改變，飛機就能朝合適的方向進行滾轉(zhuǎn)。當操控者操控遙控器上的控制桿向左，左副翼向上，飛機上機翼的升力將會改變，飛機將向左滾轉(zhuǎn)。Part3----AileronsTheelevatorsarelocatedontherearhalfofthetailplane,orhorizontalstabiliser.Thejobofthetailplaneistogenerateadownwardforcetocounteractthenaturalnose-divingtendencyofplanes,whichhappensasaresultofthenaturalforcesthataregeneratedaboutaplane'sCentreofGravityandCentreofLift.升降舵位于尾翼（水平安定面）的后半部分。尾翼的作用是產(chǎn)生一個下洗力來對抗飛機自然地抬頭趨勢，這些自然力作用在飛機上的結(jié)果是形成了重心和壓力中心。Part4----ElevatorsTheruddermakesuptherearportionoftheverticalstabiliser,orfin.Whentheoperatormovestheruddersticktotheleftonthetransmitter,theruddermovestotheleft,whiledepressingtheruddersticktotherightdeflectstheruddertotheright.方向舵位于垂直安定面的后部。當操控者在遙控器上向左打方向桿，方向舵朝左偏，而向右壓方向桿，方向舵會朝右偏轉(zhuǎn)。Part4----RudderEssentially,youcanthinkofafinasaverticalwing.Theairflowingoveritandtherudderactsinexactlythesamewayasitdoesflowingoverawingandaileron-excepttheforcesareverticalandnothorizontal.本質(zhì)上，你可以把垂直尾翼看做是垂直的機翼。流過它的空氣和方向舵作用的方式和副翼及機翼與空氣作用的方式是一樣的，只不過現(xiàn)在的空氣動力是垂直的而不是水平的。Deflectingtheruddertotheleftincreasestheairpressureontheleftsideofthefinandrudder,andsothewholebackendoftheplaneispushedacrosstotheright,thusyawingthenosetotheleft.方向舵向左偏轉(zhuǎn)使得垂直尾翼左側(cè)空氣壓力增加，所以飛機的整個尾部被推向右側(cè)，這樣機頭就向左偏轉(zhuǎn)。Par