Aeronautics

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Aeronautics

• K Sudhakar H Arya A
  Isaacs
• Centre for Aerospace Systems Design Engineering
• Department of Aerospace Engineering
• IIT Bombay, Mumbai 400076

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It Comes in All Shapes
What makes them fly?
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Contents

• Principles of Flight
• Airfoil
• Wing
• Wing Horizontal tail
• Wing Horizontal tail Vertical Tail
• Mini Aerial Vehicles
• Mini/Micro Aerial Vehicles
• Hobby flying / RC Models
• Autonomous Flight
• Navigation/Guidance/Control
• Sensors/Actuators

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Why Airfoil ?
Drag
Airfoil Shape that offers very low drag
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Lift Drag

• - Angle of Attack

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Lift Drag

• - Angle of Attack
• Lift 0.5 ? V2 C a?
• Moment 0.5 ? V2 C2 d d 0

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Lift Drag

• - Angle of Attack
• Lift 0.5 ? V2 C a?
• Moment 0.5 ? V2 C2 d d gt 0

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Lift Drag
Lift
?
Drag
Moment (Pitching)
V

• - Angle of Attack
• Lift 0.5 ? V2 C a?
• Moment 0.5 ? V2 C2 d d lt 0

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Airfoil
Moment is about 0.25C
Moment does not change with ? Lift increases with
?
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Airfoil
Moment is about 0.25C
Moment does not change with ? Lift increases with
?
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Equilibrium Stability
Unstable
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Aerodynamic Center
Point about which Moment does not change with
? 0.25 C for an Airfoil
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Airfoil, Flat Plate Or Strip of Paper
L W L X Mo 0 X - Mo/L
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Airfoil, Flat Plate Or Strip of Paper

• How to make a strip of paper fly?
• AR is large ? Like a flat plate airfoil
• h 0 ? M0 0 ? X 0
• X 0 ? Neutral
• For stability
• h lt 0 ? M0 gt 0 ? X lt 0
• X lt 0 ? Stable

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Lets Fly a Strip of Paper!
Stable
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Lets Fly a Strip of Paper!
Stable
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Lets Fly a Strip of Paper!
Stable
Hinge line of elevator
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Wing
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Wing
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Wing
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Lets Fly a Wing!
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Wing Horizontal Tail (No Fuselage)
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Vertical Tail?
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Vertical Tail? Dihedral?
?
Lets move on
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Control Surfaces
Ailerons
Elevators
Rudder
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Elevators - Pitch
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Ailerons - Roll
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Rudder - Yaw
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100 Years! How Small Has it got?
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Over the years!
How big can an aircraft get?
Mini ( 15 cm to 200 cm)
Micro (lt 15 cm)
How small can an aircraft get?
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Why Small Aircraft?

• Surveillance
• Hazard mitigation
• Military applications

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Videography Platform - IITB

• Components

Size 60 cm, Weight 870 gm
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Comparison
6 (1/4th in size) But many folds more complex
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Early Attempts to Fly

• Leonardo da Vinci
• No success in imitating birds
• Lord Cayley shows the way
• Highly integrated solutions difficult!
• Decompose and conquer

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Man Made Bird. 1992!
Flapping Flight Efficiencies have been low!
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Flapping Flight in India
To the sheer amazement of the audience, the
model began beating its wings just like a bird
and started flying!, AVIA August 2003 on Mr K
Nandakumar, Chennai
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Fixed, Flapping, Rotary Wing?

• Nature suggests flapping for small aerial
  vehicles
• Efficiency of flapping wing vehicles built by man
  not very high!

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Which Way!
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Thank You