无人机专业英语 课件 unit3 flight dynamics of uav

无人机专业英语Unit

3FlightDynamicsof

UAV1FlightDynamicsof

UAVControl

Surfaces23.13.2CONTENT3.1FlightDynamicsof

UAVNormalAxisof

Aircraft3.1.1 Axisand

RotationThethreecriticalflightdynamicsparametersoffixed-wingdronearetheanglesofrotationinthreedimensions.Thecenterpointiscalledcenterofgravity(COG),beingtheoriginofthreeaxesinthemeantime.Threeaxesarenormalaxis,longitudinalaxis,andlateralaxis.Rotationsinthreedimensionsareyaw,roll,andpitch,

respectively.Movementof

Yaw3.1FlightDynamicsof

UAVLongitudinalAxis

ofAircraft3.1.1 Axisand

RotationRollistherotationaboutthelongitudinalaxis,positivewiththestarboardwingdown.Movementof

Roll3.1FlightDynamicsof

UAVLateralAxisof

Aircraft3.1.1 Axisand

RotationPitchistherotationaboutthelateralaxis,positivewithnose

up.Movementof

Pitch3.1FlightDynamicsof

UAVAerodynamicForcesonan

Aircraft3.1.2 Aerodynamic

ForcesAerodynamicforcesarehighlydependentontheinteractionoftheatmospheremoleculeswiththeaircraftsurface,andspecificallyonthemolecules’densityandvelocity.Herethevelocityreferstotherelativevelocitybetweenatmosphereand

aircraft.3.1FlightDynamicsof

UAVAirfoil3.1.3 AirfoilA

cross section of a typical airplane wing shows the top

surface tobemorecurvedthanthebottomsurface.Thisshapedprofileiscalledan“airfoil”andtheshapeexistsbecauseithaslongbeenproven(sincethedawnofflight)thatanairfoilgeneratessignificantlymoreliftthanopposing

drag.3.1FlightDynamicsof

UAVTheGenerationof

Lift3.1.3 TheGenerationof

LiftThe

faster

a

wing

moves

through

the

air,

the

more

the

actions

are

exaggerated

andthemoreliftisgenerated.Conversely,aslowermovingwinggenerallycreatesless

lift.Theliftequalstohalfofthedensitytimesthesquareofvelocitytimeswingareatimeslift

index.3.2Control

SurfacesFor

a

airplane

to

fly

in

a

controlled

manner,

control

surface

are

necessary.Thefourmainsurfacesareaileron,elevator,rudderand

flap.Whentheairplaneisinforwardflight,itwillrotatearoundeachaxiswhenmovementtoanycontrolsurfaceismadebytheoperatororflightcontroller.Control

SurfacesTopic3

.2

Topic3

.1

Coherenceofa

paragraph.Topic3

.3

Unit

3 EnglishTraining

PartProvideevidencetosupportarguments.Thestructureofwell-organized

paragraphs.Thestructureofwell-organized

paragraphs.To

p

i

c3.

1A paragraph is a series of sentences that are organized and coherent, and are allrelatedtoasingletopic.Paragraphscancontainmanydifferentkindsofinformation.Aparagraphcouldcontainaseriesofbriefexamplesorasinglelongillustrationofageneral

point. It

might describe a place, character,

or

process; compareorcontrasttwo or more things; classify items into categories; or describe causes andeffects.Regardlessofthekindofinformationtheycontain,allparagraphssharecertaincharacteristics.Oneofthemostimportantofthese

isatopicsentence.Provideevidencetosupport

arguments.To

p

i

c3

.2

Alluniversityresearchandscholarshipisbasedonevidence,andyourownassessedworkasastudentisnodifferent.Toconvinceyourmarkerthatyouknowwhatyou’retalkingabout,youcan’tjustmakeastatementandexpectthemtoacceptit;youwillneedtoproviderobustevidencetojustifyyourpoint,showhowyouhavearrivedatyourconclusionsandprovethatit’sbasedonsolidgrounds.Coherenceofa

paragraph.To

p

i

c3.

3Repeatkeywordsorphrases.Particularlyinparagraphsinwhichyoudefineoridentifyanimportantideaortheory,beconsistentinhowyoureferto

it.Createparallelstructures.Parallelstructuresarecreatedbyconstructingtwo

ormorephrasesorsentencesthathavethesamegrammaticalstructureandusethesameparts

ofspeech.Bycreatingparallelstructuresyoumakeyoursentencesclearerandeasierto

read.Usetransitionwordsorphrasesbetweensentencesand