  The large active wing deformation is a significant way to generate high
aerodynamic forces required in bat flapping flight. Besides the twisting, the
elementary morphing models of a bat wing are proposed, such as wing-bending in
the spanwise direction, wing-cambering in the chordwise direction, and wing
area-changing. A plate of aspect ratio 3 is used to model a bat wing and a
three dimensional unsteady panel method is applied to predict the aerodynamic
forces. It is found that the cambering model has a great positive influence on
the lift, followed by area-changing model and then the bending model. The
further study indicates that the vortex control is a main mechanism to produce
high aerodynamic forces, and the mechanisms for the aerodynamic force
enhancement are the asymmetry of the cambered wing and the amplifier effects of
wing area-changing and wing bending. The lift and thrust are mainly generated
during the downstroke and almost negligible forces during the upstroke by the
integrated morphing model-wing.
