Development of a seamless morphing wing
The Cape Peninsula University of Technology (CPUT) Advanced Manufacturing and Technology Laboratory (AMTL) developed an Unmanned Aerial Vehicle (UAV) Technology Demonstrator for the purpose of testing and maturing adaptronic devices. Extending the flight envelope of this unmanned aerial vehicle by increasing its range and endurance is the next step in its development. A seamless variable angle of incidence (sVAI) morphing wing is proposed to increase the lift with little coupling to drag during takeoff; and decrease the drag with little effect on lift during climb, thus increasing the total flight performance of the aircraft. CAD models of the conceptualized sVAI wing and a conventional (CON) wing, as used on the Technology Demonstrator, were modeled. Numerical analyses on these CAD models showed that the sVAI wing concept at a 4° twist decreased the ground roll distance and stall velocity by ±17% and ±31% respectively, as compared to the CON wing in standard takeoff configuration. This allowed for ± 11.7% less power required for takeoff allowing the aircraft to get to its operational altitude quicker, thus saving fuel and reducing energy losses; and increasing range and endurance. The results also showed that the sVAI wing concept could reduce the drag during climb by ± 14%, but the lift is also proportionately reduced thus having little improvement on the climb phase of flight performance. A prototype of the morphing wing was then conceptualized and designed, using a 3D CADmodeler, and then manufactured. The product development chain produced for this morphing wing included two rapid prototyping machines and reverse engineering technologies. The chain allowed for the rapid manufacturing of light weight and intricate parts. The manufactured wing is then incorporated into a test rig to compare the actual morphing ability of the prototype to the theoretical morphing ability of the CADmodel, and thus make flight performance predictions of the actual vehicle. 3D scans were taken of the prototype and then converted to 3D CADfiles. The geometrical and topographical deformation of the prototype was then compared to that of the CAD model showing an average difference of ±1.2% and ±3% at maximum positive and negative configurations, respectively. This allowed one to make the prediction that the sVAI wing will increase the performance of the Technology Demonstrator.