Aero-structural design of joined-wing aircraft based on high-fidelity model

Abstract

The joined-wing configuration reduces induced drag and structural weight by connecting the rear wing to the front wing. In addition, the rear wing can replace the role of the horizontal tail of a conventional aircraft, thus eliminating the aerodynamic drag and weight associated with the horizontal tail. This particular shape creates a highly coupled relationship between aerodynamics and structure, which must be fully considered during the overall design process to enhance aircraft performance. In this research, an aero-structural design model of the joined-wing aircraft is constructed based on high-fidelity computational fluid dynamics and structural finite element methods. The model is able to obtain accurate aerodynamic loads for the non-planar wing and to simulate the statically indeterminate structure of the closed wing configuration. The influence of the joined-wing shape parameters on the aerodynamic and structural disciplines, as well as the influence of geometric nonlinear characteristics, deformation constraints and buckling constraints on the structural weight are all taken into consideration. The model is applied to complete the aero-structural design optimization of a high-altitude long-endurance joined-wing aircraft, and wind tunnel tests are conducted. The test results verify the credibility of the design model proposed and the validity of the design environment.