icarus redux (tdp)

8/4/2019 Icarus Redux (TDP)

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CSPIT, Changa

Icarus Redux

TheWrightDesign-TDP28thAugust,2011


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Icarus Redux 28thAugust,2011

TheWrightDesign-TDP

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TeamName IcarusRedux

PrimaryContact Name MarmDixit

PhoneNo. 9558822406

e-mailid [email protected]

SecondaryContact Name AbhishekParikh

PhoneNo. 7600121197

e-mailid [email protected]

Sr.

No.NameOfTheParticipant CollegeAndPlace

1 MarmDixit CSPIT,Changa

2 AbhishekParikh CSPIT,Changa

3 DhrupadParikh CSPIT,Changa

4 NishitKhunt CSPIT,Changa


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Inspiration Zanonia is a flowering plant familyfound inIndian subcontinent and south

eastAsia.Mostofus wouldnthaveheard of it, let alone see it.But, there

weresomewhosaw.Andafewamongthemimagined.Thezanoniaseedas

shownherewastheprimaryinspirationforthefirstflyingwingglider.Halfa

centuryon,itstillinspires.

TheConnectThe first thing we inferred after eyeing the

problem statement was that the question is

difficult, ergo the solution had to be simple. The

zanonia seed analogy worked perfectly here;

where we saw such a simple shape, glide

efficiently. It was a tailless entity, without a

propellerandnoverticalelement.Allthingsasked

ofusinthiscase.Allwehadtodowasreformthe

ideatoaworkablebasis,keepinginmindthatthe

solutionlayinsimplicity.

InitialDesignsThewackieronesofusinitiallyplannedtomutatealarge,largeZanoniaseed

and "Viola! problem solved. Backing into reality, the first thing a glider

shoulddonomatterwhatitdoesn'tis:FLY.Whatfollowsonthenextpageare

the initial designs, which were suggested and rejected, as fast as a

supermodel'sboyfriend.

Howwearrivedatthedesign.

AZanoniaSeed


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TheConceptThe main ideabehind our designswere to nullify the effectsof the rolling

pitching andyaw momentsalong with solvingthe problem oftaking a turn

midair.

StagesOfTheDesign Intheenditallboileddowntothefollowingtwodesigns.Thecommonthing inboththedesignswerefollowing.

1. Airfoil: Of everything that we saw and read and deduced, the reverse

camberairfoilwasbestsuitedforthecaseofflyingwings.Aswillbeexplained

later on, thisdesign alsodecreases the pitchingmoment and has abetter

yawcontrolthanthenormalones.

2. Planform: Probablywewereall smitten by the Horton series, pre WWII

flyingwingglider.Inspiredfromit,wemodifiedittoourpresentneeds,andto makealongstoryshort,thatbecameourplanform.

Theprimary difference then inbothourdesign was theturning mechanism

andandthecontrollingsystemforthemoments.


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Design A: has two flaps cut on each wing essentially its part but could be

rotatedaboutahorizontalaxis.Bydoingthiswewouldessentiallybesolving

our turning hurdle, but also the pitching and rolling moments could be

controlledbyslightmanouvresofthesame.Theconceptwassimple,theonly

apprehensionsaboutthethingwereitsmanufacurabilityandourcontrolover

itinflight.

DesignB:Inbetweenthetonnesofvideoswatched,andhoursonthenet&

librariesreadinganythingandeverythingwegotonthetopic,oneofushiton

the topic, 'Ailerons'. In wikipedia, though eventually we would land on

philosophy,punintended,wealsocameacross'Elevators',andthehybridof

thetwo"Elevons".Stunninginitssimplicity,andequallywithitsfunctioning,

at least theoretically, this became an integral part of the second design.

Elevons'properutilizationnullifiedthevariousmomentsandalsosolvedthe

problemofturning.


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FinalDesignThe 'Flap' sidedwings ideawas appealingdue to itsuniqueness,but it also

createdmajorhurdlesastoitscontrol.Thoughclichdintermsofgliders,its

easeofcontrolinpracticewonthegameforelevons.Thefinalsketchesour

gliderlookedthuslikethedesignB.


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Pitching,RollingAndYaw: Evenfromtheveryfirstexamplesofplaneengineeringtherehasbeenaneed

for elevators and stabilizers to control a plane during flight. Now with the

comingageoftechnology,wherejetscrackthesoundbarrierasthoughitwas

just a typical joy ride, there is a new breed of aircraft controls that have

emerged known as the "ELEVON"! Elevons are specific surfaces that utilizeairflowtoallowdirectionalchangessuchasaltitudecontrol(pitch),lateralaxis

control(roll),andverticalaxiscontrol(Yaw).Theymakeuseofacombination

ofbothtraditionalstabilizerandaileronflapcontrols,whichhavebeeninuse

sincethedawnofflight.Theseplayanimportantpartforstabilitycontrolsin

delta wing type gliders, V-type gliders where the tail is absent. An elevon

suppliesrollinputsbymovingthecontrolsoneithersideoftheaircraftthe

same distance in opposite directions. Pitch control is achieved by equally

movingbothelevonseitherupordown. Combined pitch and roll control isachievedbymovingbothelevonseitherupordowntopitchtheaircraft;one

controlisextendedfurtherthantheothertoinduceroll. Generallyailerons

onlymoveinoppositedirectionsinequalincrements.Inelevondesigns,they

canalsomoveinthesamedirectionandtodifferingdegrees.

ControlSystems


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The result of this additional range of movement is a multipurpose control

surfacethatcanbothrolltheaircraftandcauseittoclimbordescend.The

theoryandoperationoftheelevonisfairlysimpleandcapableofproducing

veryaccurateflightcontrol.Whentheelevonsaremovedequallyinopposite

directionsasconventionalailerons,theairtravelingoverandunderthewing

willpushone wingdownand theother up, thuscausing the aircraft toroll

about its axis. If they are both moved up or down equally, the air moving

eitheroverorunder thewingwill causetheaircraft'snosetoriseor dipto

climbordescend.Combinationsofrollandpitcharealittlemorecomplexand

require compound movement. Both elevons move either up or down to

induce pitch motion with one control extended further than the other to

inducerollingmotion.

ReverseCamberAirfoil As discussed later, the reverse

camber airfoil has a nullifying

effectonthe pitching moment and also it gives us a

broaderscopewithdesigns.


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Weareusingreflexedairfoil(reverse camber) for our glider. It is an airfoilwheretrailingedgehasbeenturnedupwards.ReflexairfoilgivesstableC.O.P

anditalsostabilizestheflyingplanks.Theirbenefitisintheirlowerminimum

profiledrag.AscanbeseenfromtheFBDdiagramsoftheairfoil,thereverse

camberedairfoilcreatesanoseheavymomentwhentheliftincreasesbeyond

acertainlimit.Duetothisthewingpitchesbackintotheequilibriumposition.

Thusitisalsoaself-correctingtechniqueforpitchingmoment.

AirfoilSelection

The figureshowsanairfoil withreflexmean line alongwithpositionofthemomentandforcesactingonit.Thereflexcamberlinemakesthemoment

coefficientpositive whichmeans that themomentaroundc/4 point acts in

tailheavysection.

InordertocompensatethisC.GhastobelocatedinfrontoftheC/4point. Nowsupposingthegliderpitchesup. Due tothis,we get air forceactingbehindC.G. resulting in additional nose

heavymomentbecauseliftincreases(L>L*).

With L > L* the wing will pitch down, reducing angle of attack until theequilibriumisreachedagain.

L=LiftInEquilibriumCondition

L*=Liftindisturbedposition


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WingPlanformSelection

Initiallywehaddecided to take sweptwingsas the primary design for ourgliderduetothefollowingreasons:

1.sweptbackwingsarecontributestomorelateralstability,

2.swept backwings produceless lift, so in turbulentweathertheyare less

susceptibletoabruptchanges.

3.They aredesigned with lowthicknessand high fineness ratio,hence less

formdrag,

4.Generallytheyaretapered,solessinduceddrag,

5.CapableofflyingathighMachno.asactualrelativewindspeedisatan

angle to the wing leading surface and therefore the wind component

perpendiculartothewingleadingedgeisless,andhencethewingsensesless

speedthanactual.SotheycanflytohighMachno.'s.

ThenweheardaboutthemuchdebatedblendedwingtipsusedinBoeingX-48,welistedoutitsprosandconsandeventuallywejustcametolikethelook

ofit.Stillthefewadvantagesitoffersareasfollows:

1. Fromanengineeringpointofviewthemainpurposeanddirectbenefitofwingletsarereducedairplanedrag.

2. It addedstabilityagainst the rolling moment and also decreased the rolrate.


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CentreOfGravity:Location,tal.

TheapproximatepositionofCentreofgravityandCentreofpressureofthegliderisasshowninfigure.

Thestaticstabilityofanyflyingwing(taillessaircraft)isdeterminedbythefollowingcondition

!!!

!!!

= !.! !.! ;andthismustbeequaltoorlessthanzero.

WhereCm=coefficientofmoment

Cl=coefficientoflift

!.!=DistanceofCGfromthenose

!.!

= Distance of Aerodynamic centre

fromthenose


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ThelocationofCGwithrespecttoA.C.issatisfiedwhen !!!

!!!

=0

HenceXc.g.=Xa.c. FromthiswecansaythatthefarthestaftthattheCGcanbeonaflyingwing

isdirectlyovertheAerodynamicCentre(AC).

KeepingthisinmindweworkedthewingparametersandthedesignsoastokeeptheCGawayfromtheACaspracticallypossible.

Thiscanbeseeninthediagraminthediagramaboveandtheoneinthewingparametersectionwhichfollows.


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WingConstructionandMaterials

Thisisourwingconstructionidea: Wewillfirstmakeaframeoftheentiregliderfrombalsawood. Thecentralhullregionwouldthenbereinforcedbycompressedthermocolor

likematerials.

We are actually dithering over how to cover the wing section; balsa, theobviouschoice,maymakeittooheavytofly,andontheotherhandsheetsor

fabricsmayrenderituselessincaseofstrongwinds. Also the blended winglets and the elevonshavetobe constructed intothe

wing.

Wearehopingtogetthisoneproblemwrappedupassoonaspossibleandwillnotifyyouonceitsdone.

Thematerialsofobviouschoiceo BalsaWoodo CompressedThermocolo Fabrics(Maybe)o Plastics(Maybe)


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WingParameters

Wingspan-1600 Rootchord-398.22 Tipchord-185.96 sweep-23deg wingarea-467095.84 MAClength-304.994 MACdistance-351.5537 C.G-195.07fromtop


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ALi-ionbattery. 1300mAh 11.1volts

BatterySpecifications


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Elevons ReflexedAirfoil BlendedWings NoFuel NoRudder NoFuselage NoPropellor

Our'sisnotaveryuniquedesign.Nocontouredwings,noimpossibleairfoils,not

evenafourwingedaffair.Itisbasicallyaconventionalgliderwithafewtweakshereandthere,soastoaidus,wethink,intheglider'sflight.

OurUniquenessisoursimplicity.

Theonlyquestionthenis:

WillItFly?

Uniqueness

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