Smart Engine Nacelle Strake

This paper presents the design and testing of a smart engine nacelle strake, which is designed to improve the lift-to-drag ratio on a wind tunnel model across a range of flight conditions. A traditional passive strake generates vortices that re-momentize separated flow in high-angle-of attack regimes but creates excess drag in cruise conditions, which is undesirable. To address this limitation, a smart strake concept was explored. The smart strake is a pneumatically actuated vortex generator that dynamically tailors vortex strength to the given flight condition. The concept was assessed on a half-body aerodynamic model inspired by the Boeing 737-800 and tested in the University of Washington 3x3 low-speed wind tunnel. Multiple strake configurations were evaluated using force balance measurements and flow visualization. Preliminary results indicate the smart strake design improves aerodynamic efficiency during cruise while still preserving the traditional benefits of reduced drag at stall and post-stall delivered by existing passive strakes.