Abstract
A lifting surface theory is presented for the arbitrary blade motion in incompressible flow. The theory accounts for the effects of the unsteady aerodynamics fairly exactly and is shown to simulates the blade bending-torsion flutter boundary satisfactorily which the usual quasisteady theory has hitherto failed to predict. The theory is also shown to give the results which agree well with those of other references when applied to two dimensional wing and three dimensional rectangular wings.
