Flapping Wing Flight Dynamic Modeling

Abstract

Highly agile, hover capable flapping wing flight is a relatively new area of study in engineering. Researchers are looking to flapping flight as a potential source for the next generation of reconnaissance and surveillance vehicles. These systems involve highly complicated physics surrounding the flapping wing motion and unusual characteristics due to a hover requirement not normally associated with conventional aircraft. To that end this study focuses on examining the various models and physical parameters that are considered in various other studies. The importance of these models is considered through their effect on the trim and stability of the overall system. The equations of motion are modeled through a quasi coordinate Lagrangian scheme while the aerodynamic forces are calculated using quasi-steady potential flow aerodynamics. Trim solutions are calculated using periodic shooting for several different conditions including hover, climb, and forward flight. The stability of the trim is calculated and examined using stroke-averaged and Floquet theory. Inflow and viscous effects are added and their effects on trim and stability examined. The effects of varying hinge location and the inclusion of stroke deviation in the wing kinematics are also explored. The stroke-averaged system was not found to be a direct replacement for the periodic system as the stability was different for the two systems. Inflow and viscosity were found to have large effects on the stability of the system and models accounting for the two should be included in future flight dynamic models.