Flight Testing of Optimal Blade for a High-Speed Helicopter

Abstract

In this paper, flight demonstration of the feasibility of an optimal rotor blade designed by JAXA for high-speed helicopters and the single-rotor lift-offset technology using flap differentials on the fixed-wing is reported, conducted using a 1/7 scale model helicopter named HARIOS. Flight speed of the model helicopter was measured by equipping a pitot tube and static pressure ports, and the power consumption during forward flight was obtained by summing the power consumption of various motors. These results were then compared. Although the flight demonstration was limited to an advance ratio of 0.4, it was observed that the acceleration of the aircraft increased when equipped with JAXA's optimal blade, and a significant reduction in power consumption occurred when applying the lift-offset technique. This marks a milestone in the test-flight verification for the two technologies, which had previously been investigated through wind tunnel tests and Computational Fluid Dynamics (CFD) simulations. With this flight demonstration, a significant step towards validating the effectiveness of the JAXA optimal rotor blade design and single-rotor lift-offset technology has been taken.