The aerodynamically tailored passively varying pitch propeller shows promise as a path to expand the efficient propulsive operating envelope of high-performance flying unmanned systems. Previous study focused on demonstrating the pitching performance of the aerodynamically tailored propeller blades, but did not produce test articles capable of power absorption and operational speeds for realistic flight testing. This limitation was overcome by moving from a multi-step composite monocoque lay-up, to a composite covered CNC milled foam core and a single step layup. The resulting test articles were successfully tested at 4 HP, 600% of the original test article's upper power limit. Wind tunnel data corroborates the expected pitching behavior with changing advance ratio, widening the propeller's envelope of efficient operation as compared to a conventional fixed pitch propeller. Two propeller geometries were then flown on a NRL T-15 unmanned vehicle instrumented with thrust and torque sensing on an electric propulsion motor. Flight data tracked well with wind tunnel data and demonstrated that the propeller pitch angles varied over 10 degrees during the cruise portion of the flight, and over 15 degrees when including the takeoff roll and climb-out portion of the flight. The effective scaling of the propeller power absorption demonstrates the feasibility of real-world application of the technology for performance improvement such as wide envelope efficiency, higher flight speeds, and shorter take-off distances.
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