Study of vertically ascending flight of a hawkmoth model

Abstract

This paper provides insight into the wing kinematics, the power requirement and the dynamic stability characteristics of a hawkmoth model in vertically ascending flight. The wing kinematics of the hawkmoth model is obtained based on the minimum required power assumption. The optimization process is conducted using genetic and simplex algorithms that are coupled with an artificial neural network to rapidly predict the aerodynamic force and required power. The training data for the neural network are generated from an unsteady vortex-lattice method. Compared to hover, the results in this study show the larger flapping frequency and the smaller rotation amplitude of the hawkmoth wing kinematics in ascending flight. Additionally, more power is required when the ascending speed increases. While conducting a dynamic modal analysis based on a cycle-average approach, the certain effect of the ascending speed on the modal structures of the hawkmoth model was observed.