Reduced-order modeling of a bat flying with heavy and highly articulated flapping wing

Abstract

View Video Presentation: https://doi.org/10.2514/6.2021-0344.vid A three dimensional reduced-order modeling technique is described for modelling both wing inertial and aerodynamic forces found in flapping animals and robots. The model is applied to previously-measured flight of a lesser-nosed dog-faced fruit bat (Cynopterus brachyotis) in straight and climbing flight. Quasi-steady Blade Element Momentum Theory (BEMT) is used to model the aerodynamic forces on each segment of the highly articulated wing, and Lagrangian equation of motion is adopted to describe the overall wing-body dynamics that encompasses inertial of wing. When used apart, these two distinct, independent modeling techniques yield excellent agreement in lift generation and matches trend in thrust; if combined, the simulated body trajectories match closely with that of the recorded. First time in our knowledge, the quantitative effect of wing camber was examined, which contributed to 27% of averaged lift, with a smaller price (10%) paid to drag.