Published in 49th AIAA Aerospace Sciences Meeting and Exhibit Proceedings: Orlando, FL, January 4, 2011.
Copyright © 2011 American Institute of Aeronautics and Astronautics, Inc..
This paper details the results of an investigation into the unsteady behavior of a circulation control wing using computational fluid dynamics. Oscillations in the lift coefficient of up to 10% are observed for steady state simulations. An investigation into the source of the unsteadiness is underway, and the results to date are presented. It is shown that the periodic oscillations are independent of the above the wing mounted engine effects on the cruise efficient short take-off and landing aircraft. The oscillations are also a viscous phenomenon that does not dampen as the solution marches through steady state. It is proposed that the cause of the oscillations is due to high streamline curvature at the trailing edge inboard wing section, due to flow turning caused by the slot flow normal condition at the circulation control slots. This paper presents the results into the origin of this unsteadiness.