Testing and Evaluation of Passively Actuated Vanes Operating near Propeller Tip
Weng Kheong Loh, Jamey Jacob · 53rd AIAA Aerospace Sciences Meeting · 2015
This paper discusses characteristics of of movable vanes on the propeller characteristics on a small VTOL UAV. Movable hinged vanes are positioned circumferentially in proximity to the tip of a single rotating propeller. The vanes actuate passively as the propeller RPM increases. Such systems are not widely used in any open propeller or ducted fan platform, thus operational characteristics are largely unknown. The vane behavior has been examined in a series of ground and flight tests. The vanes deflect upward and remain horizontal in parallel to the propeller plane while the vehicle is hovering or in descending flight. The upward force generated by these vanes depends largely on the proximity of the vane relative to the propeller plane, the propeller RPM, and the shape of the vane. The resulting vane deflection is dependent on these factors as well as the vane weight. This provides both stability in forward flight and improved propulsion efficiency. It is seen that the drag generated by all vanes improves the lateral and longitudinal stability of the vehicle while hovering or descending.