Copyright © A. Filippone (1999-2003). All Rights Reserved.

High Angle of Attack Aerodynamics


Airfoil Flows

All aifoils stall past a critical angle of attack (angle corresponding to the maximum lift). The (static) stall characteristics depend on the design (thickness, leading edge radius, camber, trailing edge angle) and conditions of operation (ground, out of ground, etc.).

Lift Lift

Figure 1: static stall on airfoil

Wing Rock

Wing rock is a rolling oscillation due to loss of damping at high angles of attack. This often leads to loss of control. Two particularly important cases are the highly swept wing and the slender body wing rock (for ex. forebody-delta wing). Important reviews of the problems are available in Orlik-Ruchemann (1983), Ericsson (1995), Katz (1998). See below for more.

Breakdown of Symmetric Flow

One of the features of high angle of attack flows is the appearance of asymmetrical patters and thus non symmetrical loads (rolling moment, yawing moment, side force, etc.). One case widely studied is the prolate spheroide.

Fig. 2 below shows how the breakdown in the symmetry flow on a wing-body combination can be tackled. By using a spiral trip on the fuselage both ywa and rolling moments can be greatly improved at hight angles of attack

Yawing Moment Rolling Moment

Figure 2: yawing and rolling moment on wing-body combination.

An extreme case of high angle of attack aerodynamics is the atmospheric entry of the Space Shuttle (about 40 deg at hypersonic speeds M > 20).

Separation Characteristics

High-alfa effects are particularly pronounced on delta wings, on which they have been studied for a wide range of aspect-ratio, Reynolds and Mach numbers. Three cases are of special interest: leading edge separation; separation with shock; shock-induced separation.

Related Material

Selected References

  • Chambers JB, Grafton SB. Aerodynamic Characteristics of Airplanes at High Angles of Attack. NASA TM 74097, December 1977.

  • AAVV. High Angle of Attack Aerodynamics. AGARD CP 247, 1978.
Specialised publications on

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Copyright © A. Filippone (1999-2003). All Rights Reserved.