Methods of Calculating Aerodynamic Loads on Aircraft Structures: Part I - Wing-Body Interference Effects

Abstract:
Methods are proposed for calculating the distribution of aerodynamic loads due to mutual interference effects between wings and bodies. The methods fall into two ranges of applicability: linear, and nonlinear, with angle of attack. Applicability of the linear loads methods to aeroelastic calculations is discussed. A computer program is presented which may be used to calculate interference loads at subsonic Mach numbers on a configuration consisting of (1) a body of any varying elliptic cross section and camber distribution, and (2) a wing with straight leading and trailing edges of any sweep angle, twist distribution, and camber distribution, located above or below the body centerline. Extension to the supersonic case is indicated. Generally good agreement with experimental data is found. Nonlinear wing-body interference loads are also considered. Several possible methods of representing the separated flow about a wing-body combination are proposed, and analyzed by the slender body theory. Numerical procedures are outlined, and some comparisons with experimental data are made.