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In aerodynamics, hysteresis can be observed when decreasing the angle of attack of a wing after stall, regarding the lift and drag coefficients. The angle of attack at which the flow on top of the wing reattaches is generally lower than the angle of attack at which the flow separates during the increase of the angle of attack. [8]
In fluid dynamics, angle of attack (AOA, α, or ) is the angle between a reference line on a body (often the chord line of an airfoil) and the vector representing the relative motion between the body and the fluid through which it is moving. [1] Angle of attack is the angle between the body's reference line and the oncoming flow.
[1] [2] Unlike fixed-wing aircraft, of which the stall occurs at relatively low flight speed, the dynamic stall on a helicopter rotor emerges at high airspeeds or/and during manoeuvres with high load factors of helicopters, when the angle of attack(AOA) of blade elements varies intensively due to time-dependent blade flapping, cyclic pitch and ...
An angle-of-attack indicator for light aircraft, the "AlphaSystemsAOA" and a nearly identical "lift reserve indicator", are both pressure-differential instruments that display margin above stall and/or angle of attack on an instantaneous, continuous readout. The General Technics CYA-100 displays true angle of attack via a magnetically coupled vane.
The on-ground angle of attack of the wing has to be established during the design phase. The main and nose-gear leg lengths are chosen to give a negative angle of attack relative to the ground. This ensures the wing will have negative lift until the pilot rotates the aircraft to a positive angle of attack. During landing, the reverse happens ...
Washout reduces the angle of incidence from root to tip, thereby causing a lower angle of attack at the tips Washout is clearly visible in this image of a CF-18 Hornet. Note the angle of the Sidewinder missile on the wingtip rail as compared to the angle of attack of the fuselage. The Hornet has approximately 4 degrees of washout.
The phugoid, for moderate amplitude, [1] occurs at an effectively constant angle of attack, although in practice the angle of attack actually varies by a few tenths of a degree. This means that the stalling angle of attack is never exceeded, and it is possible (in the <1g section of the cycle) to fly at speeds below the known stalling speed.
The equilibrium roll angle is known as wings level or zero bank angle, equivalent to a level heeling angle on a ship. Yaw is known as "heading". A fixed-wing aircraft increases or decreases the lift generated by the wings when it pitches nose up or down by increasing or decreasing the angle of attack (AOA). The roll angle is also known as bank ...