Lift Augmentation Flashcards
22.12.4 Explain the basic principles of trailing and leading edge flaps.
Trailing and leading edge flaps work on the principle that by increasing the effective camber of the aerofoil section over the part of the wing they are attached to. An increase in camber means a greater pressure differential being created above and below the wing.
22.12.2 Explain the basic purpose of lift augmentation devices.
Provide advantages of high lift at low speeds, without incurring the disadvantage of generating high drag at high speeds.
22.12.6 Explain the effects of lowering trailing edge flaps CL,CD,L/D ratio,CP movement, AOA and nose attitude.
CL goes up. CD goes up. L/D ratio is decreased. Drag is more than lift. CP moves rearward. AOA decreases. Nose attitude goes down.
22.12.8 Distinguish between the effects of lowering leading edge flap on angle of attack, nose attitude and movement of CP with those of trailing edge flaps.
Stalling angle of attack is increased.
Nose attitude goes up.
CP moves forward.
Note: Leading edge increase stall angle. Trailing edge reduces.
22.12.10 Given a description or diagram identify the main types of trailing edge flaps and compare their relative performance (in generating lift and drag).
The CL max goes up in order of: Simple flaps, Split flaps, Slotted flaps, Fowler flaps.
22.12.12 Given a description or diagram identify the main types of leading edge flaps.
Leading edge droop, Krueger Flap. Both open at higher AOA if the are automatic, some manual. Closed during low AOA to reduce drag. When open they increase lift and drag, by adjusting RAF.
22.12.14 Explain the basic principles of slats and slots.
Airflow on top of the wing is accelerated therefor extending the distance before separation occurs. Slat is the name of part of the leading edge that moves forward. Slot is gap created by the movement of the slat.
22.12.16 Explain the effect of operating leading edge slats on CL, Stalling angle and nose attitude.
CL increases.
Stalling angle of attack is increased.
Nose attitude goes up.
22.12.18 Show understanding of the theory of spoilers and give examples of their use.
Spoilers decrease lift and increase drag. Found on upper surfaces. Normally on jets.
