Simultaneous Aerodynamic and Structural Optimal Design of a Morphing Deformation and an Internal Compliant Mechanism

Abstract

A challenging task is to explore a compliant morphing airfoil that allows for aerodynamically superior shape change without a predefined target shape. This study addresses this task and aims to develop an optimal design method that simultaneously explores the optimal morphing shape and internal structural configuration, to obtain a morphing airfoil structure that is superior in terms of the aerodynamic and structural performance. A panel method is adopted to evaluate the aerodynamic performance, which provides a close estimate of the aerodynamic characteristics of the airfoil profile with a low computational cost and low fidelity. The structure is modeled using the finite element method. A structural configuration that improves the aerodynamic performance evaluated by the panel method is obtained by topology optimization. Additionally, the sensitivity, which is a guideline for the optimal design search to improve the aerodynamic performance, is derived to efficiently perform the optimization. The proposed design method is then applied to the multi-objective optimal design problem of morphing airfoils, considering the aerodynamic and structural performances. Through numerical examples, the validity of the proposed method is discussed by investigating the aerodynamic and structural performances of the optimized structural configurations.