An Improved Aerodynamic Model for Quasi‐Steady Simulations of Animal Flight at Moderate Reynolds Numbers

ABSTRACT We present experimental and numerical studies aimed at improving models of animal flight at moderate Reynolds numbers (‐). Quasi‐steady aerodynamic force and moment data were collected using a rectangular wing across various angles of attack, . The drag coefficient, , is well described by a simple trigonometric function, while the lift coefficient, , combines trigonometric and exponential terms—the latter capturing the linear behavior at small predicted by inviscid theory. We also derive an empirical relation for the center of pressure as a function of , allowing evaluation of the pitching moment coefficient, , about any axis. These formulas are integrated into a dynamic flapping wing model to simulate forward flight of a pigeon and a bat at different speeds. Compared to prior models, our approach yields better agreement with wingbeat frequency data, particularly at high speeds. The small angle regime proves especially beneficial, offering higher , which translates to reduced power demands and smaller body pitch variation—key considerations for the design of flapping wing robots.