Design and analysis of the control and stability of a Blended Wing Body aircraft

Future aircraft generations are required to provide higher performance and capacities with minimum cost and environmental impact. This calls for the design of revolutionary unconventional configurations, such as the Blended Wing Body (BWB), a tailless aircraft which integrates the wing and the fuselage into a single lifting surface. It has been proven in previously published works that this concept is feasible, has an efficient economical performance and is a promising candidate for solving the current air traffic problems, despite its challenging control and stability features. Moreover, the size of the vertical surfaces, such as the winglets, condition the radar detectability of the BWB model, especially for military missions. A current research problem is to find new ways to improve the aircraft conceptual design process in a multidisciplinary environment. For this project, the CEASIOM (Computerised Environment for Aircraft Synthesis and Integrated Optimisation Methods) software for aircraft design was enhanced by implementing DLR’s CPACS (Common Parametric Aircraft Configuration Scheme), as an unified and more versatile software framework. This improvement was performed in order to enable the design and analysis of future unconventional aircraft configurations, which was not possible previously. After investigating the latest developments in the BWB concept, a BWB aircraft baseline was designed and its aerodynamic behaviour and performance analysed with a special emphasis on its stability and control features. A Vortex Lattice Method (VLM) and a 3D panel method were employed for the aerodynamic analysis and both showed a close agreement. The allocation and sizing of the control surfaces was then iterated over to find the optimum winglet size for minimum drag and radar detectability conditions. All in all, the satisfactory performance of the BWB concept and the usefulness of new design software were confirmed.