The static aeroelastic characteristics of the distributed propulsion wing (DPW) were studied using the CFD/CSD loose coupling method in this study. The momentum source method of the Reynolds-averaged Navier–Stokes equation based on the k-ω SST turbulence model solution was used as the CFD solution module. The upper and lower surfaces of the DPW were established using the cubic B-spline basis function method, and the surfaces of the inlet and outlet were established using the fourth-order Bezier curve. Finally, a three-dimensional parametric model of the DPW was established. A structural finite-element model of the DPW was established, a multipoint array method program based on the three-dimensional radial basis function (RBF) was written as a data exchange module to realize the aerodynamic and structural data exchange of the DPW’s static aeroelastic analysis process, and, finally, an aeroelastic analysis of the DPW was achieved. The results show that the convergence rate of the CFD/CSD loosely coupled method is fast, and the structural static aeroelastic deformation is mainly manifested as bending deformation and positive torsion deformation, which are typical static aeroelastic phenomena of the straight wing. Under the influence of static aeroelastic deformation, the increase in the lift characteristics of the DPW is mainly caused by the slipstream region of the lower surface and the non-slipstream region of the upper and lower surface. Meanwhile, the increase in its nose-up moment and the increase in the longitudinal static stability margin may have an impact on the longitudinal stability of the UAV. To meet the requirements of engineering applications, a rapid simulation method of equivalent airfoil, which can be applied to commercial software for analysis, was developed, and the effectiveness of the method was verified via comparison with the CFD/CSD loose coupling method. On this basis, the static aeroelastic characteristics of the UAV with DPWs were studied. The research results reveal the static aeroelastic characteristics of the DPW, which hold some significance for engineering guidance for this kind of aircraft.

When a joined-wing configuration is applied to the design of solar-powered UAVs, the increasing span amplifies aeroelastic effects, while structure complexity poses greater challenges to computational effectiveness during the conceptual design phase. This paper focuses on a large-span joined-wing solar-powered UAV (LJS-UAV) engineering prototype. The structural finite element model of the whole system is constructed by developing the ‘Simplified beam-shell model’ (SBSM) and verified by a structural mode test. A numerical simulation approach is employed to comprehensively analyse and summarise the aeroelastic characteristics of the LJS-UAV from the perspectives of static aeroelasticity, flutter, and gust response. The mode test identified 30 global modes with natural frequencies below 10 Hz, indicating that the LJS-UAV possesses an exceptionally flexible structure and exhibits highly complex aeroelastic characteristics. The simulation results reveal that the structural elasticity induces significant variations in aerodynamic forces, moments, and derivatives during flight, which cannot be neglected. The longitudinal trim strategies can considerably influence the aeroelastic boundary of the LJS-UAV. Utilising the front-wing control surfaces for trim is beneficial in improving structural performance and expanding the flight envelope.

This study focuses on a high‐altitude long‐endurance (HALE) joined‐wing configuration UAV and completes a preliminary structural design based on aircraft design indices and the fundamental principles of aircraft structure design. Based on the preliminary structural design scheme and aerodynamic shape, a structural finite element model and a vortex lattice aerodynamic analysis model of the UAV are established, and the aerodynamic loads in typical states are obtained. The aerodynamic loads of the UAV are applied to a finite element model using the multipoint row method, and the structural static characteristics are obtained. The study further explores typical structural dynamic characteristics, including natural mode, static aeroelastic, flutter, and gust response characteristics. A comparison with the structural characteristics of a conventional configuration UAV with the same structural weight reveals that the HALE joined‐wing configuration UAV exhibits significant advantages in structural stiffness, mode characteristics, flutter characteristics, and static aeroelastic characteristics, whereas the gust response characteristics are essentially equivalent to those of the conventional configuration. This superiority can be attributed to the reduced wingspan while providing the same lift and effective support effect of the rear wing on the front (Frt) wings, which enhances the structural stiffness of high‐aspect‐ratio HALE UAVs. This configuration is particularly suitable for deployment in high‐subsonic HALE configurations that require close coordination with conventional tactical aircraft. By comparing with the structural characteristics of the conventional configuration UAV with equal structural weight, the paper comprehensively analyzes the structural characteristics of the HALE joined‐wing configuration and obtains the advantages and disadvantages of applying the joined‐wing configuration in HALE aircraft and defines the design direction, which lays a solid foundation for the engineering application in the next stage.

This study investigates the factors influencing the aerodynamic performance enhancement of the rear wing of the joined‐wing configuration UAVs by analyzing the flow field structure and flow mechanisms before and after airfoil optimization. Correspondingly, an optimization design concept tailored to joined‐wing aircraft is proposed. Focusing on the rear wing, a three‐dimensional design framework integrating geometric parameterization, aerodynamic simulation, and radar performance analysis was developed. The accuracy of the surrogate model was enhanced through multiround updating and optimization, and the optimal solution was derived using a genetic algorithm. The results demonstrate that the lift–drag ratio of the rear wing has been improved by approximately 9.7%. Specifically, the optimization outcomes confirm that adjusting the airfoil geometry and introducing a spanwise variation in the installation angle of control surfaces mitigates the adverse effects of front‐wing downwash on the rear wing, thereby improving the overall aerodynamic characteristics. By fully accounting for the interference of Frt‐wing downwash, this framework addresses the core challenges in rear‐wing aerodynamic optimization and provides an effective solution for enhancing the high‐altitude flight efficiency of UAVs.