introduction sir george cayley conventional configuration otto lilienthal airfoil data, first pilot...
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Introduction
Sir George CayleyConventional configuration
Otto LilienthalAirfoil data, first pilot
Alphonse PenaudRubber powered models
Octave ChanutePratt truss
Wright Brothers Control centric approach Wing warping for roll control First wind tunnel tests Adverse yaw Canard for pitch control
The Wright approach Wing warping tested on 1899 kite 1901 glider was a disappointment Wind tunnel testing leads to 1902
glider First powered flight, 1903
Problems in replication
InstabilityPitch, CG behind NPSpiral mode, Anhedral
ControlSmaller tail volumes
ConstructionalPractical limits due to scaling down
Strategy
Explore Airplane through literature
survey
Build Gliders
Glider Testing Propulsion
Prelim Report, Apr 2002
Final Design, Nov 2002
May 2002
Detailed Report, Dec 2002
Model Backup Model
Flight testing, June 2003 Done, Nov2003
Start
Strategy
Exploring a/cLiterature studyProposed solutions
Making glidersMaterial selectionPractical limits on fabricationImplementation of control mechanisms
Propulsion
Market survey forContra-rotating pushersBelts, pulleys and shaftsEngine
Test the setup
Glider Specifications1:12 scaled down modelWing Span 1.02 mLength 0.54mCanard area 6.3% of wing area, 0.0210 m2Rudder area 0.01 m2 Weight 0.15 KgBallast weight 0.040 KgWing loading 0.11 kg/m2
Glider
Glider Experience
Material selectionCentral carbon fibre box supporting
WingCanard and rudderEngine Landing gear
Central Box
Glider Experience
Material selectionBalsa wood used for
Wing ribsCanard and rudderVertical struts
Glider Experience
Monokote for wing coveringSlotted ribs for front sparJoints
Strut-spar pin joints replicatedPins lashed to spars and strutsRigging with twine thread
View of joints
Glider Experience
ControlsSteel wire for wing warpingFlexible joints in rear spar for wing warpingComplete canard moved for pitch control
(unlike original variable camber)
Weight estimationControls part
4 servos + Receiver+ Battery pack + Miscellaneous 160gm + 30gm + 120gm + 50gm =360 gm Propulsion part
Engine + Mount + Shafts, Belts, Pulleys + Fuel + Misc 335gm + 150gm+ 300gm+ 250gm+ 65gm =1100 gm
Landing gear = 150gm Structure part Carbon fiber composite + Balsa + Misc 450gm + 300gm + 250gm =1000gmTotal Maximum weight = 3 kgWing loading with this weight = 0.338 kg/m2
Thrust and Power Estimation
Max thrust required at min Cl/Cd = 12 NPower required at this Cl/Cd is 120 W
Engine of 250 W at 16000 rpmTwo 10X6 props at 8000 rpm give 15 N thrust
Thrust in lbs = 2.83x10-12
x RPM2 x D
4 x Cp x (P/29.92) x
(528/(460+T))
Propulsion
Electric motorLess weightNo starting problemsEase of maintenanceLarge battery weight (Can be used as ballast)
Lesser heating problems
Propulsion
Wankel IC engineHigh powerLess fuel weightCooling problems ?
Propulsion Belt pulley system Propeller shaft mounting replicated Contra-rotating propellers ?
6 cm
11 cm
9.3 cm
4 cm
25 cm
Side view transmission system
Front View
39.4 cm
23.5 cm
12 cm
5 cm
Unsolved problems Roll-yaw coupling ? Asymmetric yawing moment ? Pitch SAS using rate gyro? Tail and canard volumes ? Anhedral ? Landing ? Twisted belt drive ?
Cost EstimateCarbon fibre 2000
Balsa 500
Engines 8000
Belt, Pulleys, Bearings, Propeller
2900
Servos 4000
Miscellaneous 500
Total 17,900
Acknowledgements Prof. K. Sudhakar, IIT Bombay Dr. H. Arya, IIT Bombay