Design, kinematic and fluid-structure interaction analysis of a morphing wing

The application of morphing wing enables vehicles to show better aerodynamic performance in various flight conditions. This article proposes a modular bilateral triangular pyramid (BTP) unit-based morphing wing skeleton (MWS) mechanism that may achieve continuous variable span-wise bend, span-wise twist, and sweep. A lockable morphing (LM) unit with the BTP unit is designed. Based on the Denavit–Hartenberg coordinate method and motion influence coefficient method, the kinematics of MWS mechanism is conducted. The theoretical models of the kinematic characteristics of the MWS mechanism during the three morphing patterns are obtained. The kinematic simulation models of three morphing configurations of the MWS mechanism are performed. The driving speed ratio of the linear actuator of span-wise bend and twist is analyzed during the twisting phase, and the analysis shows that there be a speed ratio minimizes the coupling bend angle. By comparing the results between the theoretical and simulation models, the accuracies of kinematic theoretical models under different morphing configurations are verified. At last, this article conducted a two-way fluid-structure interaction (FSI) analysis of morphing wing to obtain the influence of aerodynamic load on the flexible skin and skeleton mechanism, as well as the influence of structural deformation on the aerodynamic characteristics. Results show that the initial and swept states have the greatest impact on the out of plane bearing capacity of the flexible skin. In addition, the out-of-plane bulging deformation located at the trailing edge of the flexible skin is beneficial for improving aerodynamic performance, while the protrusion located at the leading edge increases air resistance. These findings provide important theoretical basis for the application of the MWS mechanism.