Dynamic stability in vertically flying insect-mimicking flapping wing system

This paper provides a quantitative analysis for the longitudinal dynamic stability of a vertically flying insect-mimicking flapping wing system (FWS. In order to define the parameters in the equation of motion, the computational fluid dynamics (CFD) by ANSYS-Fluent was used. The aerodynamic forces and moment when the FWS was installed vertically and then inclined -15 and +15 degree for flight speeds of 0, 0.2 and 0.4 rn/s were computed. Through the eigenvalue and eigenvector analysis of the system matrix, we could make the formal description of the dynamic stability of the FWS. Three modes of motion were identified: one stable oscillatory mode, one unstable divergence mode, and one stable subsidence mode. Due to the divergence mode, the FWS eventually becomes unstable. However, the FWS could stay stable in the vertical flight during the first 0.5 second.