Replicating the 1903 Wright Flyer

1
Replicating the 1903 Wright Flyer
2
Introduction

• Sir George Cayley
• Conventional configuration
• Otto Lilienthal
• Airfoil data, first pilot
• Alphonse Penaud
• Rubber powered models
• Octave Chanute
• Pratt truss

3
Wright Brothers

• Control centric approach
• Wing warping for roll control
• First wind tunnel tests
• Adverse yaw
• Canard for pitch control

4
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

5
Problems in replication

• Instability
• Pitch, CG behind NP
• Spiral mode, Anhedral
• Control
• Smaller tail volumes
• Constructional
• Practical limits due to scaling down

6
Strategy
7
Strategy

• Exploring a/c
• Literature study
• Proposed solutions
• Making gliders
• Material selection
• Practical limits on fabrication
• Implementation of control mechanisms

8
Propulsion

• Market survey for
• Contra-rotating pushers
• Belts, pulleys and shafts
• Engine
• Test the setup

9
Glider Specifications

• 112 scaled down model
• Wing Span 1.02 m
• Length 0.54m
• Canard area 6.3 of wing area, 0.0210 m2
• Rudder area 0.01 m2
• Weight 0.15 Kg
• Ballast weight 0.040 Kg
• Wing loading 0.11 kg/m2

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Glider
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Glider Experience

• Material selection
• Central carbon fibre box supporting
• Wing
• Canard and rudder
• Engine
• Landing gear

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Central Box
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Glider Experience

• Material selection
• Balsa wood used for
• Wing ribs
• Canard and rudder
• Vertical struts

14
Glider Experience

• Monokote for wing covering
• Slotted ribs for front spar
• Joints
• Strut-spar pin joints replicated
• Pins lashed to spars and struts
• Rigging with twine thread

15
View of joints
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Glider Experience

• Controls
• Steel wire for wing warping
• Flexible joints in rear spar for wing warping
• Complete canard moved for pitch control
• (unlike original variable camber)

17
Weight estimation

• Controls 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
  1000gm
• Total Maximum weight 3 kg
• Wing loading with this weight 0.338 kg/m2

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Thrust and Power Estimation

• Max thrust required at min Cl/Cd 12 N
• Power required at this Cl/Cd is 120 W
• Engine of 250 W at 16000 rpm
• Two 10X6 props at 8000 rpm give 15 N thrust
• Thrust in lbs 2.83x10-12 x RPM2 x D4 x Cp x
  (P/29.92) x (528/(460T))

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Propulsion

• Electric motor
• Less weight
• No starting problems
• Ease of maintenance
• Large battery weight (Can be used as ballast)
• Lesser heating problems

20
Propulsion

• Wankel IC engine
• High power
• Less fuel weight
• Cooling problems ?

21
Propulsion

• Belt pulley system
• Propeller shaft mounting replicated
• Contra-rotating propellers ?

22
Side view transmission system
9.3 cm
4 cm
11 cm
6 cm
25 cm
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Front View
23.5 cm
12 cm
5 cm
39.4 cm
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Unsolved problems

• Roll-yaw coupling ?
• Asymmetric yawing moment ?
• Pitch SAS using rate gyro?
• Tail and canard volumes ?
• Anhedral ?
• Landing ?
• Twisted belt drive ?

25
Cost Estimate
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Acknowledgements

• Prof. K. Sudhakar, IIT Bombay
• Dr. H. Arya, IIT Bombay