Aerodynamic considerations of blended wing body aircraft

Abstract

In this paper, we present a progressive aerodynamic study of a blended wing body (BWB) configuration within a European project, MOB (A computational design engine incorporating multi-disciplinary design and optimisation for blended wing body configuration). The paper starts with an overview of various blended wing body aircraft design projects in relation to their aerodynamic behaviour. After a theoretical assessment of the ideal aerodynamic performance for the baseline configuration, viscous flow simulations were carried out to investigate the aerodynamic performance of the baseline design. The effects of spanwise distribution on the BWB aircraft aerodynamic efficiency were studied through an inverse twist design approach, combining both a low-fidelity panel method and a high-fidelity Reynolds-averaged Navier–Stokes solution method. Following the inverse design studies, the BWB wing was mapped to an aerofoil optimisation problem and the optimised aerofoil was projected back to the BWB wing to investigate further performance improvement. Finally, three-dimensional aerodynamic surface optimisation of the BWB is carried out based on both continuous and discrete adjoint approaches. A progressive improvement of the aerodynamic performance is demonstrated for the given BWB planform and the design cruise condition.