A systematic ground-based vehicle-mounted test study is conducted to investigate the propulsion/aerodynamic coupling characteristics of a distributed propulsion tandem-wing configuration aircraft at high angles of attack. Utilizing a self-developed high-precision vehicle-mounted testing platform, aerodynamic performance tests are performed on both a distributed propulsion wing section and a full tandem-wing configuration model under various rotational speeds and angles of attack. This yielded comprehensive data on coupled lift, coupled drag, and pitching moment. The research revealed the significant influence of ducted fan rotational speed on the stall angle of attack, maximum coupled lift, and longitudinal static stability. Notable aerodynamic interference effects between the front and rear wings in the tandem-wing configuration are also identified. Furthermore, a method for adjusting static stability through the differential rotational speeds of the front and rear ducted fans is proposed. This method effectively expanded the stable angle-of-attack envelope of the aircraft, providing crucial experimental evidence and data support for the aerodynamic design and control of distributed propulsion vertical/short take-off and landing aircraft.

To study the coordinated maneuverability of the wingtip-docking compound aircraft, this paper explores the changes in maneuverability from the perspectives of unit aircraft connection number and configuration. A Computational Fluid Dynamics (CFD) method is used to establish an aerodynamic database for the compound aircraft. This data is then employed to develop a dynamic model of the wingtip-hinged chain-like combined aircraft, based on a quasi-coordinate form of the Lagrange multi-body dynamics. The control inputs required for trimming in various configurations have been calculated. Next, the concept of an attitude equivalent body is proposed and its reasonableness as a reference standard for maneuverability explained. Finally, an optimization problem is constructed to evaluate the maximum attainable equivalent acceleration in the longitudinal, lateral, and yaw axes for combinations consisting of 2/3/4/5 unit aircraft in three configurations. The study identifies characteristic changes, explains the reasons, and provides a theoretical basis for configuration selection and control law design.

The aerial deployment method enables Unmanned Aerial Vehicles (UAVs) to be directly positioned at the required altitude for their mission. This method typically employs folding technology to improve loading efficiency, with applications such as the gravity-only aerial deployment of high-aspect-ratio solar-powered UAVs, and aerial takeoff of fixed-wing drones in Mars research. However, the significant morphological changes during deployment are accompanied by strong nonlinear dynamic aerodynamic forces, which result in multiple degrees of freedom and an unstable character. This hinders the description and analysis of unknown dynamic behaviors, further leading to difficulties in the design of deployment strategies and flight control. To address this issue, this paper proposes an analysis method for dynamic behaviors during aerial deployment based on the Variational Autoencoder (VAE). Focusing on the gravity-only deployment problem of high-aspect-ratio foldable-wing UAVs, the method encodes the multi-degree-of-freedom unstable motion signals into a low-dimensional feature space through a data-driven approach. By clustering in the feature space, this paper identifies and studies several dynamic behaviors during aerial deployment. The research presented in this paper offers a new method and perspective for feature extraction and analysis of complex and difficult-to-describe extreme flight dynamics, guiding the research on aerial deployment drones’ design and control strategies.