Experimental Investigation of an Airfoil with Spanwise Wavy Trailing Edge

Resumo

© 2023, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.Recently, waviness applied on leading edge of airfoils has been extensively researched. As a biomimetic solution, the also called tubercle has brought up many insights on passive flow control mechanisms and inspired other studies. Therefore, the present study aims to investigate the potential of waviness now applied on the trailing edge of airfoils. For this purpose, experimental tests in wind tunnel is carried out in order to understand the effects of different wavy geometries on the flow. A NACA 0020 airfoil is selected as a baseline profile and three configurations of waviness are tested: A = 0.11c, λ = 0.40c; A = 0.03c, λ = 0.40c; and A = 0.03c, λ = 0.11c. The phenomena are evaluated measuring forces at a single Reynolds numbers of 250,000, and correlating it with a flow topology analysis provided by an oil flow visualization technique. Main results show that the wavy model with parameters A = 0.11c, λ = 0.40c presents the best aerodynamic efficiency, with similar lift values compared to the baseline profile, but with reduced drag coefficients, also briefly delaying stall separation. Flow visualization shows that this case has larger regions of attached flow.