Experimental validation of the 3D numerical model for an adaptive laminar wing with flexible extrados

Wing drag reduction poses a real challenge in aerospace engineering. At the subsonic speed level, drag reduction can be achieved by increasing laminar flow over the wing. This work focuses on the development and validation of the numerical model of an experimental adaptive wing with improved laminar flow. The wing is composed of a rigid structure forming intrados and wing-box, flexible extrados and actuators located inside the wing-box. The extrados profile is controlled by two individually controlled actuators placed along the wing chord and acting normally to the chord. The flexible extrados is made of a woven carbon/Kevlar hybrid composite designed to allow greater flexural compliance in the chord-wise than in the span-wise direction. To allow the subsequent optimisation of the adaptive wing structure, a structural shell model of the flexible extrados is built using the ANSYS finite element software. The model takes into account the following variables: (1) reinforcement type, properties and stacking sequence, (2) laminate thickness and curvature radius, (3) boundary conditions representing the interaction between flexible and rigid wing structures, and (4) extrados-actuator coupling conditions (location, direction, force and stroke). An adaptive wing prototype has been built to verify the predicted structural response. The experimental validation of the structural model is performed using tensile and three-point bending tests followed by testing of the entire wing structure with a laboratory experimental bench.