Experimental Investigation of a Deflecting-Vane Thrust Vectoring System for Electric Ducted Fan Propulsion

Deflecting vanes are a common means of attitude control for electric ducted fan (EDF) vehicles. However, vane forces are mostly measured at a single operating condition, and the usable deflection range is usually assumed. A four-vane vectoring module fitted to a 70 mm EDF was tested on a static rig. Axial and normal forces were measured at six vane angles up to 25° and eight throttle settings from 10% to 80%. Rotational speed and exhaust velocity were measured, and smoke visualized the deflected jet. The vanes turned the force through less than the commanded angle. At each commanded angle, this shortfall varied by no more than 1.5° with throttle from 40%. At 20°, the effective vectoring angle was 16.0° to 17.2°. The thrust vectoring efficiency peaked at 20° at every throttle setting, from 40% to 20.9%. Beyond 20°, the normal force decreased and the resultant continued to fall. Hence, 20° was the best setting tested. At 80% throttle and 20°, the normal force was 1.56 N, and the resultant was 72% of the 7.89 N reference thrust. For control design, one relation between commanded and effective angle holds from 40% throttle, and commands beyond 20° add no control force.