A Computational Method for Determining Distributed Aerodynamic Loads on Planforms of Arbitrary Shape in Compressible Subsonic Flow

Abstract

The methods presented in this work are intended to provided an easy to understand and easy to apply method for determining the distributed aerodynamic loads and aerodynamic characteristics of planforms of nearly arbitrary shape. Through application of the cranked wing approach, most planforms can be modeled including nearly all practical lifting surfaces with some notable exceptions. The methods are extremely accurate for elliptic wings and rectangular wings with some notable difficulty attributed to swept wings and wings with control surface deflection. A method for accounting for the shift in the locus of aerodynamic centers is also presented and applied to the lifting line theory to mitigate singularities inherent in its formulation. Comparisons to other numerical methods as well as theoretical equations and experimental data suggest that the method is reasonably accurate, but limited by some of its contributing theories. Its biggest benefit is its ability to estimate viscous effects which normally require more sophisticated models.