Conceptual design and comparative study of strut-braced wing and twin-fuselage aircraft configurations with ultra-high aspect ratio wings

Sustainable and fuel-efficient next-generation air transportation demands a step change in aircraft performance. The ultra-high aspect ratio wings (UHARW) configuration is one key enabling strategy for improving aircraft aerodynamic efficiency and reducing fuel consumption and emissions. Unconventional aircraft configurations and advanced airframe technologies are required to address the large bending moment and shear stresses in the UHARW structure. This paper considers two promising unconventional configurations for adopting UHARW design, including strut-braced-wing (SBW) and twin-fuselage (TF), with advanced airframe technologies, i.e., active flow control, active load alleviation, and advanced airframe structures and materials. Three typical missions, including short-range (SR), medium-range (MR), and long-range (LR), are considered for aircraft design. A conceptual design and performance analysis framework for SBW and TF configurations is developed in this paper. According to the mission profile and top-level requirements proposed for each mission, an SBW and a TF configuration are designed, respectively. A comparative study is carried out to determine the best-in-class configuration of the corresponding mission to evaluate the potential of SBW and TF configurations for next-generation sustainable aviation applications. The results showed that the TF configuration has a better wing weight reduction effect than the SBW configuration, and the MR-TF and LR-TF aircraft have lower takeoff weight and fuel weight than those of the SBW aircraft for the same mission. However, due to the adjustment of the cabin dimensions for the SR-TF aircraft, the SBW configuration outperforms the TF configuration in this mission.