| An experimental study was conducted to characterize the effects of pitching motion on vortex shedding behavior in the wake of a flatback airfoil. Experiments were conducted on a static, rigidly mounted airfoil as well as an oscillating airfoil in a wind tunnel facility at the University of Wyoming. Particle image velocimetry was used in conjunction with proper orthogonal decomposition to show that the vortex shedding does behave differently depending on the dynamic configuration of the airfoil. The results show that fundamental vortex shedding from the blunt trailing edge is present in both the static and dynamic case whenever the flow is attached. In a case where the flow separates under dynamic stall conditions, the flow physics are dominated by the dynamic pitching motion, and trailing edge vortex shedding is only present during the attached portion of the pitching cycle. In another case, it was shown that the organization of the vortex shedding changes depending on the point in the oscillation cycle. This dynamic behavior has an impact on the aerodynamic characteristics of the blade. |
