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THE analysis and prediction of the nonlinear lift due to the vortex flow associated with low-aspect-ratio wings has received considerable attention in the literature for many years. Methods of solution based on complex mathematical models have generally failed, and no generalized empirical methods have been developed. However, within the past several years E. C. Polhamus of the NASA Langley Research Center has proposed and verified through comparison with experimental data an analytical method for sharp-leading-edge wings of zero taper ratio. 1 The method is based on a leading-edge-suction analogy proposed by Polhamus. 2 Extension of the suction analogy to plane rectangular wings has been accomplished in work unpublished at the time of this writing by J. E. Lamar, also of NASA Langley. A method for analyzing sharpedged, flat wings of arbitrary planform is presented here as a logical extension of the suction-analogy concept.The well-known Polhamus method for wings with pointed tips divides the total lift into two components, a potential-flow term, C(L P ), and a vortex-lift term, C(L V ):The full potential flow lift C(L P ) is assumed to exist since the vortex induced flow reattachment maintains the Kutta condition at the trailing edge. The potential-flow term is then given by cosa = K p sina cos 2 a (2)where K p is the normal-force slope given by potential-flow theory:(3) d sina cosa.

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