Active Flow Control of a Pitching Turret Flow Field Using Closed-Loop Feedback Control

Experimental testing of an active ow control system on a three-dimensional, nonconformal turret has been performed at a diameter based Reynolds number of 2:0 10. Active ow control was achieved using dynamic suction and various open and closed-loop feedback control algorithms in an e ort to determine the most e ective and e cient control scheme for reducing aero-optic distortions in the vicinity of the turret aperture. Dynamic surface pressure and PIV measurements have been used to better characterize and understand the ow eld in order to evaluate the active control system. From this research, it has been shown that dynamic suction has the ability to manipulate the separated ow above the turret aperture and can signi cantly alter the characteristics of the aperture ow eld. Open-loop control was shown to be the most e cient form of control when set to the proper suction levels, but the merit of closed-loop feedback control has also been shown, especially for cases where the aperture of the turret is dynamically pitching. Generally, open-loop control systems require scheduling of the active control system during pitching where a closed-loop control system would not due to the sensing capabilities.