34th AIAA Applied Aerodynamics Conference, 13-17 June 2016, Washington, D.C.
This paper presents the novel nonlinear formulation of the Vortex Lattice Method approach for calculating the aerodynamic properties of lifting surfaces. The mathematical model is constructed by using two-dimensional viscous analyses of the wing span-wise sections, according to strip theory, and then coupling the strip viscous forces with the forces generated by the vortex rings distributed on the wing camber surface, calculated with a fully three-dimensional vortex lifting law. The numerical results obtained with the proposed method are validated with experimental data and show good agreement in predicting both the lift and pitching moment, as well as in predicting the wing drag. The technology demonstrator was modeled after an aircraft wing tip section, and was fitted with a composite material upper skin whose shape can be morphed, as a function of the flight condition, by four electrical actuators placed inside the wing structure. The nonlinear VLM results were compared with balance forces/moments measurements taken during subsonic wind tunnel tests performed at the National Research Council Canada.
American Institute of Aeronautics and Astronautics