Aerodynamic Interference of Wing-Pylon Body Combinations at Low Subsonic Speeds.

Abstract : A method for determining the subsonic aerodynamic interference between a planar wing with pylons and a single axisymmetric body has been developed and evaluated. The wing and body solutions were obtained independently using a simple horseshoe vortex system and a three-dimensional point source distribution, respectively. A vortex image system based on the two-dimensional theory of images was then added to the body to maintain the tangent-flow boundary condition in the non-uniform wing flow field. Both the influence of the vortex image system within the body and the body flow field effects at the wing were evaluated. No significant change in the wing vortex strength distribution resulted so that it was unnecessary to iterate the isolated wing solution. The theoretical results for incompressible flow were compared with pressure distributions obtained from low-speed wind tunnel tests of the wing-body configuration. The correlation was generally good. (Author)