Gradient-Based Aerodynamic Optimization of an Airfoil with Morphing Leading and Trailing Edges

Abstract

This article presents a gradient-based aerodynamic optimization framework and investigates optimum deformations for a transonic airfoil equipped with morphing leading and trailing edges. Specifically, the proposed optimization framework integrates an innovative morphing shape parameterization with a high fidelity Reynolds-averaged Navier–Stokes computational fluid dynamic solver, a hybrid mesh deformation algorithm, and an efficient gradient evaluation method based on continuous adjoint implementation. To achieve a feasible morphing shape, some structural properties of skin and wing-box constraints were introduced into the morphing shape parameterization, which offers skin length control and enables wing-box shape invariance. In this study, the optimum leading and trailing edge deformations with minimization of drag at this cruise stage were searched for using the adjoint-based optimization with a nested feasible morphing procedure, subject to the wing-box, skin length, and airfoil volume constraints. The numerical studies verified the effectiveness of the optimization strategy, and demonstrated the significant aerodynamic performance improvement achieved by using the morphing devices. A lambda shock pattern was observed for the optimized morphing leading edge. That result further indicates the importance of leading edge radius control.

Experimental Validation and Evaluation of a Coupled Twist-Camber Morphing Wing Concept

“…Still, within the camber morphing research, aero-structural high-fidelity optimization of an adaptive trailing edge for transonic flight predicts decreased fuel burn by more than 5% [4]. Optimum deformations for a transonic airfoil with morphing leading and trailing edges were obtained using high-fidelity aero-structural modeling, showing significant aerodynamic performance improvement [5].…”

Aerodynamic Characteristics of Morphing Supercritical Airfoils for Aircraft with All-Stage High Performance

“…Aiming at the aerodynamic topics of the both leading-edge and trailing-edge variable-camber technology, Kong et al [54], Lu et al [55], and Menshchikov and Somov [56] used numerical simulation or combined with a wind tunnel experiment to analyze the influence of both leading-edge and trailing-edge variable camber on the aerodynamic performance of airfoil at low-speed stage. Meanwhile, Zhang et al [57] used high-fidelity aero-structural modeling to investigate the optimum deformations for a transonic airfoil, and the results reveal that morphing leading and trailing edges shows significant aerodynamic-performance improvement compared to morphing leading or trailing edges individually. Wang et al [58] performed research on the influence of both leading-edge and trailing-edge variable camber on aerodynamic characteristics and optimization of drag reduction under transonic condition.…”