Aerodynamic Design Of The Blend-wing-body Subsonic Transport

In resent years, the market of civil aviation asks for better economical efficiency which, in some extent, means airplanes should be able to carry more people or goods. This situation demands new and more advanced airplanes. To meet this demand, many aircraft companies and institutes present a new collectivity layout of the airplane named Blended-Wing-Body Transport or All-Wing Aircraft. Since the disadvantages of this layout, problems of stability and maneuver ability, have been overcome, and because of its light weight, high starting efficiency, and good stealth, the BWB becomes the preferred layout.In this paper, on the basis of the study and analysis of the previous results of the BWB researches, we implement the layout on the practical design of a big civil airplane. The result of the paper is that at a given cruise Mach number, we design a BWB transport whose flying off weight is about 200t.The process of the work is as follows. The flying off weight and the thrust weight ratio are first fixed according to the design discipline of aircraft, and the geometry parameters are then identified according to the request of aerodynamics. The geometrical model of the aircraft is then got by the CAD software. After that, the structure mesh for CFD simulation is generated by GRIDGEN. The surface pressure distribution and the maximum Lift-to-Drag Ratio can be obtained by solving N-S equations. The results of the simulation are analyzed carefully and a modified geometrical model is proposed, which has a bigger Lift-to-Drag Ratio. The aim of the paper is to get a modified geometrical model which has a Lift-to-Drag Ratio more than 17.