Feedback Controlled Deployment of Covert Inspired Wing Flaps

Abstract

Unmanned aerial vehicles (UAVs) are anticipated to play an increasingly active role in complex missions that require high difficulty maneuvers. However, current UAVs are limited in mobility by their inability to efficiently perform high-angle-of-attack maneuvers at low Reynolds numbers. This project draws inspiration from the design of bird wings and their ability to enable performing high angle of attack maneuvers with relative ease. Studies have shown that this is made possible within the distributed system of wing feathers through a passively deployed, self-adaptive wing feather called the covert feather. The deployment of this feather in-flight helps correct for flow reversal, prevent stall, and enhance lift. Previous studies investigating effects of bio-mimetic covert flaps in conditions generated by a wind tunnel have revealed that passive deployment of the flaps only enable the best post-stall lift when their deflection angles are at an optimal configuration for a particular angle of attack.

The objective of this project is to investigate whether adopting active deployment of the covert flaps to maintain optimal angles design will further enhance the effects of lift that passive deployment achieved. To do so, a mechanical and controller system framework for an active flow control device based on a single actively deployed flap on the upper surface of an airfoil is designed and implemented. A rigid PLA flap is attached to a 3D printed NACA2414 airfoil via a hinge joint. Active deployment is achieved via a double geared mechanism actuated via a discrete RC servo housed in a cavity of the airfoil. This will serve as a blueprint for the development of a full spatially distributed system that incorporates feedback flow control.