Dynamic Response of Circulation Control for Step and Sinusoidal Inputs

A numerical study of the dynamic performance of a circulation controlled (CC) airfoil is performed to explore the feasibility of using circulation control as means of gust suppression. Steady and unsteady two-dimensional computational fluid dynamics (CFD) simulations were initially validated using published data. The dynamic performance of a CC airfoil was subsequently assessed. The response of the CC airfoil to step and sinusoidal inputs were obtained from unsteady CFD simulations. It was found that the actuation speed of circulation control is significantly faster than a conventional mechanical flap at the same flight condition. Additionally, the lift response to a step input was found to be very similar to the Küssner function.