Development of a hybrid (rigid-flexible) morphing leading edge equipped with bending and extending capabilities

Abstract

The development of the bench model of a hybrid (rigid-flexible) morphing leading edge is presented in this paper. The distinctive feature of this design centers on compounding a fully rigid nose with a flexible structure to create a seamless morphing leading edge. The rigid nose guarantees a precise shape control in the aerodynamically critical region of the wing whereas the flexible structure allows for an increase in both chord length and its camber. These improvements offer potential solutions to many of the challenges reported in the literature about the existing morphing wing designs. In order to evaluate the feasibility of the hybrid (rigid-flexible) concept and to demonstrate the aforementioned improvements, a bench model is developed and tested in-house. This paper focuses on the analysis performed to develop this model, including (1) aerodynamic shape optimization to devise the desired drooped shape; (2) geometry optimization to specify the dimensions of the rigid nose; (3) finite element analysis to characterize the skin component of the flexible structure; and (4) finite element analysis to estimate the actuation authority. Overall, the numerical and experimental results reveal the inherent advantage of the hybrid (rigid-flexible) concept from the smart structure standpoint; however, significant considerations are required to advance the technical readiness level of this design to a commercially viable solution for aircraft manufacturers.