Experimental Investigations of a Dual-Mode Skin-Actuated-Camber with Embedded Twist (SACET) Morphing Wing

A dual mode Skin Actuated Camber with Embedded Twist morphing wing is developed to approximate a bell-shaped lift distribution and the associated tip vortex free wake. Three morphing concepts are conceived for a rectangular wing using simple geometric models that link actuator motion to local rib twist. The concepts use independent servo driven ribs, a gear train that drives multiple ribs with a single shaft, and a linkage based single rod layout under a flexible skin. One configuration with embedded rib servos and TPU skin is fabricated and tested in the University of Dayton Low Speed Wind Tunnel and is compared with rigid wings that has the target twist and camber distributions. Measured lift, drag, and quarter chord moment coefficients show that the current prototype does not achieve the commanded twist, because the twist only morphing configuration behaves like the untwisted wing, while the rigid twisted wing exhibits the expected changes in lift, drag, and moment. The results indicate that higher twist authority and reduced skin resistance are required before the full aerodynamic benefits of dual mode morphing for bell shaped loading can be realized.