面向扑翼翼面运动参数的优化设计

The flight of an ornithopter depends on the motions of the flapping wing. The optimal aerodynamic characteristics of a specific flapping wing will be obtained when using an optimized motion strategy. Furthermore, it provides a design basis for the transmission mechanism of a flapping wing aircraft. However, there is currently a lack of effective method for motion optimization in design stage to determine a set of optimal motion parameters for a given wing. In this paper, the unsteady vortex lattice method (UVLM) is applied to calculate the aerodynamic effect caused by the flapping motion. To verify accuracy of the aerodynamic calculation method, the result is correctly compared with existing experiment data. Then based on the DIRECT (divide rectangle) global optimization algorithm, the flapping kinematics parameters are iteratively optimized to maximize the propulsion efficiency. The results show that the optimization method can effectively solve the optimal parameters of flapping kinematics parameters and improve specific aerodynamic performance. The average thrust calculated by the optimization algorithm in this paper has a 104% numerical improvement compared to that of the baseline motion. Besides, it indicates that reducing the lift and thrust constraints are beneficial to the optimization to achieve a higher propulsion efficiency in the design process. The maximum propulsion efficiency without aerodynamic constraints in this paper is improved by 46. 8% compared to that of the baseline motion.