Nonlinear Static Aeroelastic and Trim Analysis of Highly Flexible Joined-Wing Aircraft

The static aeroelastic responses and trim solutions of a high-aspect-ratio all-wing joined-wing aircraft are presented. The basics of the computational framework are the coupling of a geometrically nonlinear three-dimensional (3-D) corotational double-spar structural model with a 3-D nonplanar vortex lattice aerodynamic model. Inertia relief is exploited in the aeroelastic calculation for the first time to account for the effects of mass distribution on the static deformations of the unconstrained flying aircraft. A static structural test of the outer wing and a qualitative flight test are conducted to verify the numerical model. Numerical results of the aeroelastic deformations, lift predictions, the aerodynamic coefficients and their derivatives, as well as the trim solutions are presented and analyzed in detail and compared with rigid, linear, and nonlinear structural models. The present work provides sound insights on the aeroelastic behaviors of the flexible high-aspect-ratio joined-wing aircraft, which emphasize once more the importance of taking into account the geometric nonlinearity in the design and analysis of flexible aircraft.