Fig. A1. Effects of grid and time step on aerodynamic force production. (A) Grid sensitive analysis for aerodynamic force coefficients over a flapping cycle. Three grid systems are used: c, a coarse grid system (wing: 33x35x19, body: 33x35x35); fn, a fine grid system (wing: 45x45x31, body: 45x47x95); and ft, a finest grid system (wing: 45x45x31, body: 57x55x121). (B) Time step sensitive analysis for aerodynamic force coefficients over a flapping cycle. Two time steps are used: t1, time step dt=0.005; t2, time step dt=0.0025.