Active Flow Control at Low Reynolds Numbers by Periodic Airfoil Morphing

Abstract

This paper investigates the application of a periodically deforming airfoil surface for the purpose of flow control at low Reynolds numbers. A physical model has been fabricated by bonding Macro Fiber Composite (MFC) actuators to the underside of a NACA 4415’s suction surface. The results presented build on work by Jones et al.1 First, the behavior of the surface when actuated at a range frequencies is investigated through a combination of photogrammetric and laser sensor measurements. Second, the aerodynamic performance of this novel flow control technique is presented. It is shown that when the actuation frequency ‘locks-in’ to the surface motion significant improvements in performance are observed in a flight regime notorious for poor airfoil behavior.