angle of attack

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angle of attack

[′aŋ·gəl əv ə′tak]
(aerospace engineering)
The angle between a reference line which is fixed with respect to an airframe (usually the longitudinal axis) and the direction of movement of the body.
(mining engineering)
The angle in a mine fan made by the direction of air approach and the chord of the aerofoil section.

Angle of Attack

 

the angle between the direction of trans-lational motion of a body and some characteristic direction on the body. The characteristic direction may be, for example, a chord of an airplane wing or the axis of symmetry of a projectile or a rocket.

angle of attack

angle of attackclick for a larger image
Angle of attack is the angle between the wing chord plane and the relative air flow.
The acute angle between the chord line and the relative airflow. Often referred to as an angle of incidence—which it is not. The angle of attack should not be confused with the pitch angle or attitude of aircraft, which are angles relative to the horizontal while the angle of attack is in respect to the relative airflow. It is referred to also as alpha (α).
References in periodicals archive ?
It was observed that the solid blockage due to the current test stand resulted in 0.4% to 0.7% increase in the effective freestream velocity for angles of attack of 90[degrees] to 0[degrees].
2: Blades at Low, Medium & High Angles of Attack S.NO AEROFOIL ANGLE OF VELOCITY OF MAXIMUM CONFIGURATION ATTACK (degree) AIR (m/s) POWER (W) 1 NACA 0010 10 10 313 2 NACA 4412 10 10 308 3 NACA 4415 10 10 199 4 NACA 4418 10 10 313 5 NACA23012 10 10 374 6 NACA23015 10 10 675 7 NACA23018 10 10 193 8 NACA63218 10 10 168 Fig.
With the difference of pitching moment coefficient corresponding to the two angles of attack before and after the initial angle of attack, the static derivative can be further calculated by deriving the difference of angles of attack.
As previously mentioned, the angle of attack is varied from 0[degrees] to 180[degrees] with an increment of 2[degrees], making a total of 46 angles of attack for each configuration.
Passage from separated to non-separated flow performance occurs at lower angles of attack than the critical angles of attack that correspond to the beginning of flow separation.
Angles of attack of hand models of 0[degrees], 45[degrees] and 90[degrees], with a sweep back angle of 0[degrees] (thumb as the leading edge) were used for the calculations (Schleihauf, 1979).
At certain angles of attack, it would close off the fuel flow to the engine, causing it to stall.
Since different airfoils (wing designs) behave differently in an air stream, the three models are expected to differ under varying angles of attack and wind speed.
The ground effects of large-swept delta wings were also studied under different angles of attack [12-15].
Anything other than a fixed-pitch prop is designed so its blades can pivot in the propeller hub, allowing different angles of attack, including feathered, flat pitch and reverse.
Because of the wake-induced velocity, the freestream velocity vector will be rotated by the induced angle of attack, [[alpha].sub.i], as shown in Figure 4 and the induced angles of attack for the two wings can be obtained as