Aerodynamics Flashcards
Bernoulli’s Principle
Increased speed equals lower pressure. Lower pressure on the airfoil higher pressure on the lower portion of the wing. Venturi principle. High Pressure pushes low pressure up
Chord line
line through the middle of the aircraft wing
Upper surface camber and lower surface camber
top and bottom of the wing, and the mean camber runs in between the perfectly or equal distance… flaps increase camber line.
Leading edge vs tailing edge
front of the wing, back of the wing
angle of attack
angle between the chord line and relative wind
Critical Angle of Attack
the point at which a plane can stall
Relative Wind
Runs parallel and opposite of the wings path
Why does air accelerate on the top of a wing?
The Coanda affect
As we increase angle of attack we get what?
Wind deflection down from the lower surface camber and pushes the plane up
What affect do wing tip vortices have on our plane
Induces drag
Wake Turbulence is strongest when the plane is what?
Heavy clean and slow
Equation for lift
LIft= coefficient of lift x pressure(Density) x velocity squared x surface area divided by two
What are the two types of drag?
Induced and Parasitic
What is parasitic drag?
- Form- designed into the airplane, the least time it takes for the air to move from the front to the back of the aircraft the better
- Interference: different airflows that intersect. Anything at a 90 deg angle on the plane causes interference drag
- Skin Friction: all surfaces have an imperfectly smooth surface. Fluid air running into that induces drag
Maneuverability
the aircrafts ability to maneuver and not break
Controllability
The reaction your plane has to your inputs
What are the two types of Stability?
Static stability is the initial tendency
Dynamic Stability how it reacts over time
Static Stability: What is positive, neutral, and negative stability?
Positive returns, negative gets worse, neutral remains the same
Vertical axis
controls yaw, rudder
Longitudinal Axis
length of plane, controls bank, ailerons
Lateral Axis
pitch, stabilator, wings
Center of lift is normally aft or infront of CG
aft of CG
How does moving the CG affect our performance
if the cg is too far forward it affects several aspects of performance
Cruise Performance: decreased with a forward CG
Stall Speed: Increases
Stall Recovery: Better
Take off performance: Longer ground roll, not a great climb
Landing performance: trouble rounding out or flaring
Stability: better
Aft CG affects
Cruise performance: better
Stall Speed: lowers
Stall recovery: worse
Take off performance: Worse, tail strike possibilities.
Landing performance: trouble round out flare
Stability: Better
