A New Structural Design Concept for Blended Wing Body Cabins

Abstract

This paper outlines a new concept for a pressure cabin design for blended-wing-body aircraft. An overview is presented of the wide oval cabin and why it is believed to be a possible alternative to existing designs of non-circular pressurized cabins. The perimeter of the oval cross section is formed by four smoothly connecting arcs of different radii. One arc forms the upper surface of the fuselage, one arc forms the lower surface, and two arcs at either side form the side of the fuselage. At the interconnection nodes of each of the arcs a prismatic box structure caries the tension and compression loads that result from pressurization. This structural layout forms a large uninterrupted internal space that allows for a flexible cabin configuration. Furthermore, this concept encompasses synergy in aerodynamic and structural design by having the lower member of the prismatic box structure forming the passenger floor and having the cabin outer skin panels be directly part of the aerodynamic shell. A method has been developed that estimates the weight of the cabin based on pressurization loads and main geometrical parameters of the cabin (height, span distribution, and length) as well as the geometry of the airfoil in the plane of symmetry of the cabin. A cabin design for 400 passengers shows a total cabin weight of 34 metric tons, and sufficient cargo volume for 36 LD3 containers.