Approximate added-mass method for estimating induced power for flapping flight

A method that uses the added mass of vortex sheets was developed to estimat e induced power in flapping Right for birds and insects. This new method ha s advantages over existing methods. First, it is valid for flights with any forward velocity. Second, this method can be used to determine the effects of most kinematic parameters of flapping wings on induced power, like the inclination of the stroke plane, amplitude of the flapping angle, and the m ean flapping angle. For hovering flight this method has the same accuracy a s methods based on the Rankine-Froude momentum theory or on vortex ring the ory. When the forward velocity is large, this method agrees with the moment um theory for a fixed wing.