Just sat the ATPL Principles of Flight exam today! All the above is way over that level. I will try to give you some basic numbers and facts that may be of use.
AoA is defined as the angle between the chord line (a straight line joining the leading edge and trailing edge) and the relative airflow.
For a typical light aircraft in the cruise phase of flight (for a Cessna 152 lets say IAS of 90 knots) the aoa will be of the order of 4 degrees. This is fairly typical for many aircraft.
The wing off course is not set in a direct line along the aircraft longitudinal axis but is inclined at an angle called the angle of incidence. Hence a 737 cruises with around 2.5 deg nose up (aircraft pitch angle) but the wing is probably about 4 deg aoa. Hence why in the cruise you feel like you are walking uphill when going from row 10 to the forward toilet (because you are!) and hence the No 2 cabin crew, who will be at the rear, has bigger muscles than the No1 and No 3!
The wing will stall at an aoa of approximately 15 degrees.
The wing of typical light aircraft is not symmetrical, the upper surface has greater curvature then the lower, so as to increase the pressure differences and generate more lift. This is called camber. Hence at 0 deg AoA a light aircraft wing will produce a small amount of lift. Typically zero lift is produced at a small negative AoA on such an aerofoil, of the order of -3 to -4 deg.
As you increase the angle of attack of the wing it produces more and more lift, and the centre of pressure moves forward. Max lift is just before stalling AoA. At stall AoA the lift drops sharply and the centre of pressure moves back aft (those causing the nose to drop and help you to recover from the stall).
The lift equations is as follows :
Lift = Coefficient of lift x 0.5pv2 x S
p = pressure, v2 = velocity squared, S=surface area of the wing
Coefficient of lift is harder to define, but is basically to do with the shape and design of the wing and increases with an increase of AoA.
Hope thats of benefit, e-mail me at
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