Experimental Evaluation of a NACA 0021 Airfoil Employing Shape-Memory Alloy for Active Flow Control
Abstract
Current aircraft use actuators to alter the wing geometry and generate the ideal flight characteristics which is known to be a method of active flow control. By replacing the heavy electric and hydraulic actuators currently used in aircraft wings with lighter and smaller shape memory alloys (SMAs), the mass of an aircraft can be reduced. Therefore, research was conducted to design and build an airfoil using SMAs as the actuator for improving the airfoil’s aerodynamic performance. The SMA actuated airfoil was evaluated using advanced flow diagnostic methods and was found to operate with a higher lift coefficient than the non-actuated airfoil for certain angles of attack (AoAs). Testing the SMA airfoil at various frequencies also revealed its effect on the flow recovery after actuation. Lastly, comparison of the SMA to comparable actuators revealed that the SMA wires had a force to mass ratio that was over 100 times larger.