03.4 - Applied Aerodynamics
MORPHING LEADING-EDGE TUBERCLES ON CESSNA 172 WING
G. Abate¹, H.P. Monner¹; ¹German Aerospace Center (DLR), Germany
Sinusoidal modifications of the leading-edge also called “tubercles” are applied to the Cessna 172 wing in order to study their aerodynamic effect especially at post-stall conditions. Originally, tubercles characterize the Humpback whale flippers, and they help these giant animals to increase their speed and maneuverability into the water by acting like flow control devices. Studies showed that tubercles are similar to vortex generators and wing fences: they re-energize the leading-edge flow by generating vortices that can block most of the spanwise flow leading to a delay in flow separation and stall. It has been shown that they can successfully be applied to fans and wind turbine blades, but not many works highlight their positive effects on wing applications. Therefore, the present study wants to conduct an aerodynamic analysis of tubercles applied to the leading-edge of the Cessna 172 wing. A particular attention will be given to three design parameters: amplitude, wavelength, and wingspan location. These variables characterize every single tubercle configuration, and their combination results in different aerodynamic flow effects. The aim of this analysis is to give some insights on tubercle parameterization and their geometric characteristics in order to achieve stall delay and relevant aerodynamic improvements in off-design regimes. Moreover, as mentioned before, since the positive effect of tubercles is relevant only at some flow conditions or regimes, the present work wants to consider the possibility of designing tubercles as morphing structures that are deployed only when needed by changing the shape of the leading-edge wing thanks to smart materials and actuators.