Wing weight model for conceptual design of nonplanar configurations

Abstract

Unconventional aircraft designs, such as nonplanar wings, are being considered for the next generation of transport aircraft. In order to determine the suitability of such designs, conceptual design tools are needed which are both sensitive to these unconventional configurations and capable of obtaining results rapidly. Wings represent a large contribution to an aircraft's empty weight and there are many commonly used conceptual design tools which can accurately estimate this component's weight for conventional designs. However, nonplanar wings can have very different aerodynamic loadings and structural details so existing models cannot be easily extended to treat these complexities. This paper shows the development of a conceptual-level wing weight model which combines a fully-stressed cross-section method with an equivalent beam finite-element structural solver using loads derived from a nonplanar vortex-lattice method. This model is able to obtain accurate aerodynamic loadings for nonplanar wings and can model the statically indeterminate structure of closed wing configurations. It was shown to be as accurate as current approaches when analyzing conventional wings and it is able to show the details of nonplanar wing structures. This model will enable more meaningful multidisciplinary analyses of both conventional and unconventional wing designs by accurately and rapidly predicting both the weight and internal structural details of these designs.