Bubble Burst Control Using Smart Structure Sensor Actuators for Stall Suppression

A smart structure sensor actuator system that can be used to enhance the application of the burst control plate attached to the leading edge of the airfoil and to serve as a stall-avoidance system, was investigated. Measurements were conducted in a subsonic suction type wind tunnel with freestream turbulent intensity of 0.16% at a freestream velocity of 10 m=s. A NACA 631-012 airfoil with span of 200 mm and chord length of 200 mm was employed. The height of the burst control plate is controlled by the angular movement of two identical micro servos that are typically used for radio-controlled planes. Since the sensors on the airfoil are coupled with different small tubes and electric wires, every possible effort was made to minimize the interference with the force measurements. When the optimum plate height is reached, sufficient energy is drawn from the mainstream and that flow reattachment exists. The maximum lift coefficient of the airfoil with autonomous actuation system is increased as compared to the value of the clean airfoil.