Detection of a Stall of a Symmetric Airfoil and Its Feedback Control (Demonstration for an Increasing Angle Mode)

Abstract

Lift and drag characteristics of a symmetric airfoil with miniature electromagnetic actuators have been investigated when an angle of attack has been increased at a constant speed in a low Reynolds number range. It was revealed that the dynamic actuation of the miniature actuators was effective to delay the stall. A basic example of a feedback control, in which the time series lift was used as the input signal to detect the stall and had a role to start the actuation of the miniature actuators, was tried and it could achieve the increase of the lift, that is, it could delay the stall. Second example of a feedback control including the increase and decrease of the angle of attack of the airfoil was demonstrated to be effective not only to recover the lift after the stall but also to maintain the high lift situation.