An Experimental Investigation on the Asymmetric Wake of an Oscillating Airfoil
نویسندگان
چکیده
Bio-inspired aerodynamic designs have been mutually promoted by the studies on flapping wings in the past decades. Among the tons of researches topics, the wake formation/structure of an oscillating airfoil is more attractive, and it results in the development of both numerical methods and flow diagnostics techniques. In this paper, wake formation behind a sinusoidally piching NACA 0012 has been studied with PIV measurements. The evolution of wake structures with increasing Strouhal number was reproduced successfully. With further experiments, the effect of Strouhal number, the amplitude and mean value of AOA on the asymmetric wake formation were also investigated. Results showed that the distance between vortex street became larger with increasing amplitude, while mean strength of vortices declined. Besides, the asymmetric wake formation was strongly dependent on the mean. Specifically, based on our experiments, the direction of wake asymmetry was changed at a ̅ and .
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