11.1 Aerodynamics Flashcards
What is the main function of a stabilator?
Eliminate Mach tuck caused by shock wave formation
What is the purpose of vortex generators?
They provide the boundary layer with additional energy to prevent flow separation
What is the effect of pulling the control column rearwards?
Elevators deflect upward, aircraft nose up
How do ailerons respond if the pilot rolls the aircraft to the left?
The aileron on the left wing moves up and the aileron on the right moves down
How does area rule effect an aircraft’s transonic flight performance?
It reduces wave drag
What are the two types of shock waves that are formed in supersonic flight?
Normal and oblique
What happens to air temperature behind a shock wave?
The temperature rises
Airflow behind a normal shockwave does what?
Decreases to subsonic
Airflow behind an oblique shock wave does what?
Remains at supersonic but decreases a bit
Where does velocity reduce and temperature increase?
Stagnation point
What are the 4 flight controls on the wings?
. Slats
. Flaps
. Spoilers
. Ailerons
What is the main function of the horizontal stabiliser?
Eliminate mach tuck
Wha5 stalls first the lifting canard or wing?
Lift canard
Control canards produce how much lift?
0%
What angle is the control canard set to?
0%
What is a boundary layer control at wing root?
Stall strip or wedge
The ruddervator has two functions, what are they?
. If both surfaces moved simultaneously = elevator function
. If both surface moved oppositely = rudder YAW
What is the most important control?
Pitch
Why does the tip stall first on swept wing?
Spanwise flow
How would you roll right?
Right aileron deflects up, left aileron deflects down.
Subsonic air in flight is …….?
Incompressible
Define the critical Mach number
The highest Mach number without being supersonic
What is the lift increase for a plain flap?
55%
What is the lift increase for a flower flap?
95%
What is the lift increase for a slat?
35%
When a supersonic airflow passes through a shock wave, what happens to temperature?
Temperature increases
When a supersonic airflow passes through a shock wave, what happens to pressure and density?
Both increase
When a supersonic airflow passes through a shock wave, what happens to velocity?
Decreases
How do ailerons respond if pilot rolls the aircraft to the left?
Left aileron deflects upwards, right deflects down
What percentage does a split edge flap increase lift by?
65%
What percentage does a slotted flap increase lift by?
70%
If nose goes upward what way does the trim tab deflect?
Down
What control does a control canard allow?
Pitch control
What do stall wedges allow?
Stalling at the root instead of tip
What is a transonic profile also know as?
Rear loaded profile
What do you use to correct the aircraft when the centre if pressure moves back causing Mach tuck?
Trimmable horizontal stabiliser
What does an expansion wave do to supersonic airflow?
Increases the supersonic airflow speed
