2. AerodynamicsAerodynamics
“A branch of dynamics that deals with the motion of air and
other gaseous fluids and with the forces acting on bodies in
motion relative to such fluids.”
Source: Merriam-Webster Online
7. LiftLift
In addition to allowing the aircraft to fly,
changing the force of lift on various parts
of the aircraft allows the aircraft to be
maneuvered in flight
◦ We will review how lift is created first
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8. Physics ReviewPhysics Review
Newton’s laws summed up.
◦ 1st
- A body at rest tends to stay at rest and a
body in motion will stay in motion unless acted
on by a force.
◦ 2nd
– Force = Mass * Acceleration
◦ 3rd
– For every action there is an equal and
opposite reaction
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9. Bernoulli’s Theory of LiftBernoulli’s Theory of Lift
Bernoulli’s principal summed up:
◦ as the velocity of a fluid increase, its internal
pressure decreases.
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11. LiftLift
Changing the basic shape of the airfoil
allows for different flow patterns about the
wing changing the amount of lift created
Changing the amount of lift created by
various airfoils on the aircraft allows the
pilot to maneuver the aircraft in-flight
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14. Chord LineChord Line
Chord Line : An imaginary line leading
from the leading edge to the trailing edge
of an airfoil
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15. Angle Of AttackAngle Of Attack
Angle of attack: Referred to as “AOA”, is
the angle made up between the chord line
and the relative wind
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17. Airspeed and StallsAirspeed and Stalls
We can only increase AOA so much before
we induce an aerodynamic stall
Though airspeed is often associated with a
stall, a stall can happen at any airspeed
and in any attitude if the critical AOA is
exceeded
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18. StallsStalls
For a given airfoil, we can only increase
AOA so much before we experience an
aerodynamic stall
Airfoil in normal flight Airfoil in stalled condition
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22. Maneuvering FlightManeuvering Flight
The flight controls allow pilots to
maneuver the aircraft by changing the
pressure distribution (and the amount of
lift created) on various parts of the
aircraft.
The primary flight controls do this by
changing the AOA to change the lift
created thereby allowing the aircraft to
pitch bank and yaw
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29. DragDrag
Parasite / Skin friction drag
◦ Airflow is stagnate near the surface of the wing
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30. DragDrag
Parasite / Interference drag
◦ Airflow is disrupted by how various objects are
arranged on the aircraft
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32. DragDrag
Induced drag
◦ Any time a wing is producing lift their is
induced drag
◦ The higher the AOA the more induced drag
◦ Slow aircraft = high AOA = high induced drag
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33. DragDrag
Combined drag curves gives us total drag
◦ 1 airspeed gives us least total drag
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36. Wingtip VorticesWingtip Vortices
Airflow moves from
high to low – at the
wing tips it is allowed
to spill over the top
creating a vortex
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39. Secondary Flight ControlsSecondary Flight Controls
On most training aircraft secondary flight
controls are limited to:
◦ Flaps
◦ Trim
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40. Secondary Flight ControlsSecondary Flight Controls
Flaps
◦ Allow decreased minimum flight speed
◦ Allow increased drag / Steeper descents
Often used during landing for this purpose
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46. ConclusionConclusion
Concluding RemarksConcluding Remarks
What was not discussed
◦ Transonic flow
◦ Drag-divergence Mach number
◦ Supersonic flow
◦ Wave drag
◦ Swept wings
◦ Compressibility effects
◦ Boundary layer theory
◦ The history of aerodynamics
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47. Ask your question:Ask your question:
For more information
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khan/
Email: zubayer_007@yahoo.com
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