CAREER: An Experimental Investigation of the Flow Fields over Bio-Inspired and Finite Span Wings Undergoing Dynamic Stall

Clarkson University, Potsdam NY

Investigators

Abstract

0845882 Bohl Airfoils are central components of many important technologies, including wind turbines, turbomachinery and aircraft, and better understanding of flows over airfoils is critical to their continued development. When an airfoil is placed at a sufficiently high angle of attack, the flow over the surface can separate causing loss of lift or stall. Stall is usually detrimental to performance. Historically, the study of airfoil dynamics has centered on airfoils placed at fixed angles of attack. This view is insufficient to describe the physics of airfoils in motion, where the developed lift and the stall angle are considerably higher. Under these conditions the loss of lift can be abrupt causing rapid changes in the aerodynamic and loading characteristics. This phenomenon is known as dynamic stall (DS). This experimental study will develop a bio-inspired strategy to control or delay DS and quantify the velocity and vorticity fields in the critical region near the airfoil leading edge for finite aspect ratio airfoils. Dynamic stall plays a key role in the development of two transformational technologies: wind power generation and the development of high-performance aircraft. It is widely anticipated that the Joint Strike Fighter will be the last manned fighter developed for the US Department of Defense. Removing the pilot increases the performance potential by increasing the allowable forces experienced during extreme maneuvers for which dynamic stall is central. Dynamic stall also results in high unsteady loads on wind turbine blades which, if controlled, can increase their performance and durability. The lack of experimental data for finite span wings undergoing DS hinders the development of predictive models and represents. The PI's educational objectives include the development of new curricula for college and high school courses. Graduate students will gain experience by acting as mentors to the undergraduates who will enhance their educational experience through focused research. Students will be recruited from primarily under-represented groups using Clarkson University's pipeline programs such as the NSF sponsored S-STEM program. A senior-level problem-based undergraduate course in bio-fluid mechanics will be developed addressing the concept of biomimicry using the PI's research as a case example. A similar collaborative effort will be undertaken with a local high school. Once developed, these materials will be disseminated to other area teachers through the Clarkson University Office of Educational Partnerships.