Mission Adaptive Compliant Wing – Design , Fabrication and Flight Test Mission Adaptive Compliant Wing

Abstract

Compliant flap structure is already recognized as a device that can reduce or eliminate flow separation due to conventional flap system. It also has the ability to minimize drag and increase lift coefficient. However the manipulation of this compliant structure is not fully exploited for internal airfoil structure involving structural control deformation and flexibility. the main objective of this research is to design, fabricate, testing and quantify the aerodynamic and utilize the structural elasticity performance of a compliant mechanism airfoil for a high altitude and long endurance aircraft. The design is targeted to minimize the force required to morp surfaces while maintaining maximum stiffness to withstand external loading. A model of airfoil with embedded compliant mechanism has been develop and driven by servo motor and also tested on real fight testing. The aluminium and polymer composition are chosen to provide a smooth skin on the upper and the lower surface. The testing covered about the envelope expansion, natural laminar flow and high rate flap deflection. Through testing the author found that the wing produces more lift and afford to attach the laminar flow over 60% on the airfoil surface when the flap was deflected. However the laminar boundary layer significantly increase another 10% and able to generate lift when the flap system is activated by compliant mechanism. The success of high capability of embedded compliant mechanism shows the great potential in variable airfoil geometric capability. the adaptive compliant flap shows the capability and effectively control the upper and lower surface pressure distribution, minimize the flow separation and wing drag. The test measurement confirmed the extensive run of laminar flow on the airfoil and the flap was successfully operated in high altitude, low temperature environment without any operational restriction and limitation.