Research>Flow control>Manoeuvre effectors>Circulation Control

Background

For a regular aerofoil with a rounded leading edge and sharp trailing edge, the circulation* round the aerofoil, and hence the lift it generates, is proportional to the angle of attack. The principle of Circulation Control (CC) is based on the modification of the circulation round a body without a sharp trailing edge by the tangential injection of fluid momentum on the surface of the body. Thus by use of CC, the lift from an aerofoil section can be varied with the section angle of attack remaining constant. This is in principle the same way that a conventional trailing edge flap works, but with CC the whole geometry remains fixed. The main application of CC is for high lift, where CC can be used to increase the performance of existing flaps or enable equivalent performance to be obtained from smaller flaps.

The use of CC as a manoeuvre effector for roll instead of a conventional aileron is driven by the desire to reduce the signature of low observable aircraft. The CC work at Manchester is part of the FLAVIIR project funded by BAESYSTEMS and EPSRC.

Presentations

Flapless Flight Demonstrator Experience at Manchester, February 2007

Publications

Sparks, R., Michie, S., Gill, K., Crowther, W.J., ‘Development of an Integrated Circulation Control / Fluidic Thrust Vectoring Flight Test Demonstrator’, 1^st International Conference on Innovation & Integration in Aerospace Science Queen’s University Belfast 4^th & 5^th August 2005 (CEIAT 2005-0086)

Telegraph article, October 2005

The original CC work at Manchester was carried out by Stephen Frith

*The circulation theory of lift is at the core of understanding how a wing works, and goes way back to the beginning of aviation. However, its not what you learn at school because it requires some rather abstract concepts and is not really necessary if all you are trying to get across is the 'Bernoulli principle'.