The design and optimisation of a prototype sailplane

Abstract

The science of aerodynamics can be traced back thousands of years to its beginnings, however remarkably, only one human life span separates the first heavier-than-air aircraft flight from the present day. Unfortunately, during this time little information has been released on the design methods of the high performance aircraft that best utilise the aerodynamic theory. The sailplane is one such example. This thesis seeks to investigate the theoretical foundation of un-powered aircraft design as well as implement computational methods to design and optimise a prototype sailplane based on its aerodynamic efficiency. The investigation considers the influence of a number of important features, including the airfoil, wing planform, fuselage and tail assembly geometries, and the inherent interference between these components. The overall aim of this study is to determine the appropriate combination of these components in order to provide the greatest L/D ratio over a range of intended flight speeds. The results of the investigation found two possible optimal aircraft configurations. These configurations were each functions of differing geometric parameters and were both considered as valid solutions. It is hoped that the information contained within this thesis will further enhance sailplane design methods and consequently aid to the betterment of the aerodynamic field.