Active Control of Separation from the Flap of a Supercritical Airfoil

Abstract

Active flow control in the form of periodic zero-mass-flux excitation was applied at several regions on the leading edge and trailing edge flaps of a simplified high-lift system t o delay flow separation. The NASA Energy Efficient Transport (EET) supercritical airfoil was equipped with a 15% chord simply hinged leading edge flap and a 25% chord simply hinged trailing edge flap. Detailed flow features were measured in an attempt to identify optimal actuator placement. The measurements included steady and unsteady model and tunnel wall pressures, wake surveys, arrays of surface hot-films, flow visualization, and particle image velocimetry (PIV). The current paper describes the application of active separation control a t several locations on the deflected trailing edge flap. High frequency (F+ Y 10) and low frequency amplitude modulation ( F i A I FZ 1) of the high frequency excitation were used for control. Preliminary efforts to combine leading and trailing edge flap excitations are also reported.

High-Lift System for a Supercritical Airfoil: Simplified by Active Flow Control

“…The low Reynolds number SHL results on the BART model 2,3 indicated that the momentum required to control flow separation on the trailing-edge flap of the model was significantly higher than the momentum required for controlling leading-edge flow separation and higher than the momentum required for controlling flow separation on the NACA 0015 at flight Reynolds numbers. The BART data 2 also indicated that combining multiple excitations would increase control authority.…”

“…Low Reynolds number results of Melton et al 1,2,3 showed that periodic excitation was effective at controlling leading-edge flap shoulder separation, increasing the maximum lift coefficient, C L,max , by 10-15% at low (less than 5…”

The failure of delayed detached eddy simulation for flow control over a hump using synthetic jet actuator

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Vehicle types classification using deep neural network techniques

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