Flying-wing aircraft are considered to have great advantages and potentials inaerodynamic performance and weight saving. However, they also have manychallenges in design. One of the biggest challenges is the structural design ofthe inner wing (fuselage). Unlike the conventional fuselage of a tubeconfiguration, the flying-wing aircraft inner wing cross section is limited to anoncircular shape, which is not structurally efficient to resist the internalpressure load. In order to solve this problem, a number of configurations havebeen proposed by other designers such as Multi Bubble Fuselage (MBF),Vaulted Ribbed Shell (VLRS), Flat Ribbed Shell (FRS), Vaulted ShellHoneycomb Core (VLHC), Flat Sandwich Shell Honeycomb Core (FLHC), YBraced Box Fuselage and the modified fuselage designed with Y bracereplaced by vaulted shell configurations. However all these configurations stillinevitably have structural weight penalty compared with optimal tube fuselagelayout. This current study intends to focus on finding an optimal configurationwith minimum structural weight penalty for a flying-wing concept in a preliminarydesign stage.A new possible inner wing configuration, in terms of aerodynamic shape andstructural layout, was proposed by the author, and it might be referred as‘Wave-Section Configuration’. The methodologies of how to obtain a structurallyefficient curvature of the shape, as well as how to conduct the initial sizing wereincorporated.A theoretical analysis of load transmission indicated that the Wave-SectionConfiguration is feasible, and this was further proved as being practical by FEanalysis. Moreover, initial FE analysis and comparison of the Wave-SectionConfiguration with two other typical configurations, Multi Bubble Fuselage andConventional Wing, suggested that the Wave-Section Configuration is anoptimal design in terms of weight saving. However, due to limitations of theauthor’s research area, influences on aerodynamic performances have not yetbeen taken into account.
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