Weissinger's model of the nonlinear lifting-line method for aircraft design

A method is presented that allows for the calculation of nonlinear aerodynamics within the time constraints of the conceptual design phase. This method was developed with characteristics of a design oriented analysis technique: adequate accuracy, computational efficiency, accuracy and speed tradeoff and minimal time for geometric input and modification. In addition, the code can be readily coupled to other analysis codes, e.g. with a structural analysis code, which is important for the use in multidisciplinary design optimization. The method is based on Weissinger's lifting-line model. In addition, it incorporates the Biot-Savart law, Kutta-Joukowski theorem, and airfoil lift data. Results of swept and unswept wings show very favorable agreement with experiment.