Optimization of aerodynamic efficiency for twist morphing MAV wing

 Twist morphing (TM) is a practical control technique in micro air vehicle (MAV) flight. However, TM wing has a lower aerodynamic efficiency (C_L/C_D) compared to membrane and rigid wing. This is due to massive drag penalty created on TM wing, which had overwhelmed the successive increase in its lift generation. Therefore, further C_L/C_Dmax optimization on TM wing is needed to obtain the optimal condition for the morphing wing configuration. In this paper, two-way fluid-structure interaction (FSI) simulation and wind tunnel testing method are used to solve and study the basic wing aerodynamic performance over (non-optimal) TM, membrane and rigid wings. Then, a multifidelity data metamodel based design optimization (MBDO) process is adopted based on the Ansys-DesignXplorer frameworks. In the adaptive MBDO process, Kriging metamodel is used to construct the final multifidelity C_L/C_D responses by utilizing 23 multi-fidelity sample points from the FSI simulation and experimental data. The optimization results show that the optimal TM wing configuration is able to produce better C_L/C_Dmax magnitude by at least 2% than the non-optimal TM wings. The flow structure formation reveals that low TV strength on the optimal TM wing induces low C_D generation which in turn improves its overall C_L/C_Dmax performance.