Calculation of Potential Flow about Arbitrary Three Dimensional Wings using Internal Singularity Distributions

Abstract

SummaryA first order panel method has been developed for calculating the incompressible potential flow about arbitrary three-dimensional wings. The method utilises a distribution of source and vorticity singularities on the mean camber surface of the wing and solves for the distribution by satisfying the boundary condition of zero normal flow at selected points on the surface of the wing. The method takes less computing time compared to other existing first order methods for the comparable numerical accuracy. This method can handle wings having cusped trailing edges and thin sections.

A low-speed aerodynamic model for harmonically oscillating aircraft configurations

“…At any spanwise station the wake vortex element shed from the trailing edge during any small time interval t has a circulation equal and opposite to the corresponding change of the sectional circulation. Therefore just aft of the trailing edge the strength of shed vorticity is given by Y"(x",r)8x = 8t (9) Assuming that the shed vorticity is moving with the mean velocity U x , we have, Six = U^Sit. Thus tf»Yw(* te .0 = -ar (10) The vortex element at a general point x of the wake at time t was shed at an earlier time (t -x/U x ).…”

“…This has been elaborated in Ref. 9. The quadrilateral elements on the wetted surface of the fuselage carry uniform source distributions.…”

“…A few methods' 58 ) are available that can handle the harmonically oscillating wing-body configurations in the pitching mode. A numerical method, based on an internal singularity distribution technique' 9 ), has been developed here for the calculation of steady and unsteady pressure and lift distributions on the harmonically oscillating aircraft configuration in incompressible flow. In the present method, for wing and wing-like components, source and vorticity singularities are distributed on the respective mean camber surfaces, while the fuselage wetted surface carries a source distribution.…”