Preliminary aerodynamic investigation of small box-wing aircraft

Abstract

This thesis explores the various aerodynamic aspects of the box-wing design - a non-planar aircraft configuration, which under certain conditions, displays reduced induced drag. The box-wing is similar to a biplane with wings that are joined at the tips by endplates, forming a box structure when viewed from the front.  As an unconventional planform, the fundamental capabilities and characteristic of the box-wing differ significantly from those of the conventional monoplane. Despite a recent increase in research focused on efficiency improvements utilising non-planar systems, including the box-wing, little of this has focused on application to small aircraft. Small, in the context of this thesis, being a maximum takeoff weight not exceeding fifty-seven hundred kilograms. In order to gain a great understanding of the potential for the reduction of induced drag of such aircraft, three interconnected investigations have been conducted. To conduct these investigations, a combination of analytical simulation and parametric analysis utilising vortex lattice method (VLM) are used. To assess the specific induced drag advantage of the box-wing configuration, a comparison aircraft is selected for reference. The geometric constraints of the reference aircraft are applied to the new box-wing, and the resulting aerodynamic characteristics are compared with those of the base aircraft. In the case of the third investigation, using parametric analysis within VLM, it was first necessary to create and validate a model of the reference aircraft