Aerodynamics Flashcards
(38 cards)
Name the 3 axis of the airplane
Longitudinal (Roll)
Vertical (Yaw)
Lateral (Pitch)
What is parasite drag?
Skin friction drag
Increases as speed increases
Double airspeed and then parasite increases by 4Xs
Cut airspeed in 1/2 and then parasite drag will become 1/4
What in induced drag?
Drag caused by AOA as you increase lift
Slower you go the more AOA then more induced drag
What is Max L/D?
Lowest point of overall drag
Max range
Max distance glide
What are the 4 turning tendencies?
Torque- propeller turning to the right, tries to roll the airplane to the left
spiraling slipstream- propeller creates a spiral of air that contacts left of the tail causing yawing motion to the left
P-factor -right side of propeller, descending blade has a higher angle of attack, yaws to the left
Gyroscopic precession- propeller acts like a gyroscope
What are the 3 different types of parasite drag?
1) skin friction drag -smooth the surface the less drag
2) form drag -result of an objects general shape in relation to relative wind
3) Interference drag -generated by the mixing of airflow streamlines between the airframe components such as the wing and fuselage… as it flows around it interacts well or not well either minimizing or creating more drag
Why does induced drag decrease in ground effect?
Ground effect reduces the effectiveness of your wingtip vorticies… reduction in down wash, and allows you to maintain a slightly lower AOA which reduces your induced drag as well.
What is the lateral axis of the aircraft?
Pitch
What is the longitudinal access of the aircraft?
Roll
What is the vertical axis of the plane?
Yaw
What V speed is drag the lowest?
Vs
When does induced drag start to form?
When does parasite drag start to form?
What is adverse yaw?
Adverse yaw is the tendency of an airplane to yaw in the opposite direction of the turn. For example, as you roll to the right, your airplane may initially yaw to the left.
Keep coordinated to counter adverse yaw.
When are wingtip vortices the greatest?
Heavy, clean, and slow…
Clean b/c high AOA
What way do wingtip vortices move?
Airflow moves out from under the wing, swirled around the tip, and tries to enter low pressure regional at the top
What is Bernoulli’s principle?
Increase in the speed of a fluid occurs simultaneously w/ a decrease in pressure
What is Newton’s 3rd Law?
For every action in nature this is an equal and opposite reaction
What are the 4 phase of a spin?
Entry phase
Incipient phase
Developed phase
Recovery phase
aircraft spin is an aggravated stall that causes autorotation about the spin axis and a downward corkscrew path for the aircraft. The outboard wing is less stalled than the inboard wing when the aircraft spins around the vertical axis
What is our aircraft spin recovery?
PARE
Power back
Ailerons level
Rudder opposite of spin
Elevator/ nose down
What do we need for a spin to occur?
Airplanes wings uneven AOA is what causes the rotation at stall… wings are extended beyond their critical AOA
Adverse yaw
What’s the difference between Vs0 and Vs1?
Vs1 is stall speed in the clean configuration.
Vs0 is stall speed landing flap configuration.
Vs is stalling speed or min steady flight speed at which the airplane is controllable.
What is a standard rate turn?
360 deg turn completed in 2 min
360/ (2*60)= 3 deg/ sec
180 deg turn completed in 1 min
What is the difference between the forward slip and side slip?
Forward slip used to lose altitude by increasing drag. Lowered wing points toward direction of flight and nose points away…
Side slip used to keep the airplane aligned on the runway when landing in a crosswind. Nose points towards direction of flight.
