Final Review Flashcards
(138 cards)
What is the atmosphere made of?
78% Nitrogen, 21% Oxygen, 1% Other
Effect of temperature on the atmosphere
affects the density of the air because when air is heated it expands
Effect of humidity on the atmosphere
affects the density of the air because water vapor is less dense than air
Effect of altitude on the atmosphere
affects the density of the air because there are fewer air molecules the further up you go
What is Standard Day?
59 degrees F
Sea level
Zero humidity
41 deg. N Lat.
Four forces
Thrust, Lift, Drag, Weight
Thrust
Thrust is a mechanical force generated by the engines to move the aircraft through the air
Lift
Lift is a mechanical force generated by a solid object moving through a fluid
Newton’s 3rd Law Applies: For every action there is an equal and opposite reaction
Drag
Drag is a mechanical force generated by a solid object moving through a fluid
Newton’s 1st Law Applies The Law of Inertia: If a body is at rest or moving at a constant speed in a straight line, it will remain at rest or keep moving in a straight line at constant speed unless it is acted upon by a force
Weight
Weight is a force caused by the gravitational attraction of the Earth
If the 4 forces are balanced …
the aircraft cruises at constant velocity and altitude
If the forces are unbalanced
the aircraft accelerates in the direction of the largest force
Bernoulli’s Principle
As the velocity of a fluid increases the pressure exerted by the fluid decreases
Coanda Effect (Downwash)
A moving stream of fluid in contact with a curved surface will tend to follow the curvature of the surface rather than continue traveling in a straight line
LIFT acts upward from the
Center of Pressure
WEIGHT acts downward from the
Center of Gravity
Changing Camber
increasing the angle that the wing meets the air
Changing Lift
The higher the AOA, the greater velocity of the air, and smaller area of the wing exposed the faster air
Parts of an airfoil
Leading edge, Chord line, Upper camber, Trailing edge, Lower camber, Angle of Attack (AOA)
Dihedral
angle of angle of wing from plane to wing tip
Mean Camber Line
refers to an imaginary line, created mathematically, when you subtract the distance from the chord line to the lower camber from the distance from the chord line to the upper camber
Lift Equation
L = CL½V2Sρ
Types of Drag
Parasite, Induced, Profile
Parasite Drag
The drag produced by air flowing over the surfaces not involved in producing lift