Numerical Simulations and Experiments of a Flapping Butterfly

摘要

This paper treats the flapping-of-wings of a butterfly, which is rhythmic and cyclic motion. The objective of this paper is to clarify the principle of a stable flapping-of-wings flight. For the purpose, a dynamics model of a butterfly is derived for analyses by Lagrange's method, where the butterfly is considered as a rigid body system. A simple method and a vortex method are then applied to make a simulator where the methods calculate the aerodynamic force. An experimental system with a low-speed wind tunnel is constructed for fundamental data of flapping-of-wings motion, where the system measures the aerodynamic force and the motion simultaneously by a balance and a optical measurement system. Validity of the mathematical model is examined by comparing the measured data with the numerical results. A periodic orbit of a flapping-of-wings flight is searched so as to fly the butterfly model. Furthermore, numerical computation examines the stability of a flapping-of-wings motion generated by a neural network oscillator.