Methods of approaching an accurate three-dimensional potential solution for a wing

Abstract

There is a great need for more accurate data on the aerodynamic derivatives of swept-back wings in order to solve problems of stability, control and flutter. As one step in the search for these data the estimation of the three-dimensional potential solution is essential, and if it is to be of value the degree of accuracy of any approximation must be known beyond question. This report gives attention to some fundamental aspects of the vortex-sheet theory for determining the distribution of lift on a finite wing. The accuracy and limitations of some existing approximate forms of the theory are discussed. With special reference to the labour of computation an iterative approach to an accurate solution is suggested, and the general mathematical expression for the distribution of lift required to give an exact solution for a Vee wing is considered. It is proposed - (a) That, with the specific purpose of checking the Falkner (R. & M. 1910, 1943) vortex-lattice theory, the iterative procedure should be applied to a wing of constant chord with acute hyperbolic leading and trailing edges (see Fig. 3). (b) That by choosing suitable functions calculations should be undertaken to determine a reliable potential solution for a Vee wing (see Fig. 2) in an inclined stream. (c) That further study is needed before calculations can usefully be nudertaken to improve the accuracy of existing methods of estimating the characteristics of deflected controls.