Copyright © A. Filippone (1996-2001). All Rights Reserved.

Aerodynamic Drag

Lift-induced Drag


This type of drag is due to the vorticity produced by a lifting wing (induced drag or vortex drag) and is expressed as momentum deficiency in the wake. This type of drag can be a drawback of high-lift systems. Typically, a strong vortex is released at the tip.

The dissipation of this vortex farther downstream is one of the source of loss, but this is of viscous nature. The inviscid nature of the drag is also due to the downwash created in the slipstream, which on turns is related to an induced angle of attack.

Reduction Methods

Methods used for the minimization of the induced drag make use of techniques to diffuse this vortex and redistribute the wing loading. The methods include:

For lifting wings some of the devices commonly designed are the following

Tip Devices

The methods listed above are used for the reduction of the vortex drag produced at the tip.

Selected References

  • Hoerner SF. Fluid Dynamic Drag, Hoerner Fluid Dynamics, 1965.

  • AGARD. Special Course on Concepts for Drag Reduction, AGARD Report R-654, 1977.

  • AGARD. Special Course on Subsonic/Transonic Aerodynamic Intereference for Aircraft, AGARD Report R-712, 1983.

  • AGARD. Aircraft Drag Prediction and Reduction, AGARD Report R-723, 1985.

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Copyright © A. Filippone (1996-2001). All Rights Reserved.