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This paper introduces a low-boom aircraft optimization design method guided by equivalent area distribution, which effectively improves the intuitiveness and refinement of inverse design. A gradient optimization method based on discrete adjoint equations is proposed to achieve the fast solution of the gradient information of target equivalent area distribution relative to design variables and to drive the aerodynamic shape update to the optimal solution. An optimization experiment is carried out based on a self-developed supersonic civil aircraft configuration with engines. The results show that the equivalent area distribution adjoint equation can accurately solve the gradient information. After optimization, the sonic boom level of the aircraft was reduced by 13.2 PLdB, and the drag coefficient was reduced by 60.75 counts. Moreover, the equivalent area distribution adjoint optimization method has outstanding advantages, such as high sensitivity and fast convergence speed, and can take both the low sonic boom and the low drag force of the aircraft into account, providing a powerful tool for the comprehensive optimization design of supersonic civil aircraft by considering sonic boom and aerodynamic force. [ABSTRACT FROM AUTHOR]

The flapping wing rotor (FWR) is a novel aerial vehicle that combines the aerodynamic benefits of both a flapping wing and a rotary wing. By utilizing the passive rotation effect resulting from the flexible deformation of the center symmetric flapping wing, the FWR can enhance its lift force. However, previous research has neglected to explore the mechanism behind the flapping-rotation motion of a flyable FWR, which elucidates its lift advantage compared to conventional flapping motion. Additionally, the impact of varying wing number on the flapping-rotation motion and performance of the FWR has not been taken into consideration. Therefore, it is imperative to conduct an experimental analysis to ascertain the impact of flapping-rotation decomposition and varying wing quantities on FWR. In this study, our prior vehicle design, which exhibited consistent stable hovering and maneuvering capabilities, is employed to construct the flapping wing rotor experiment system. Through this unique experimental system, the effects of flapping-rotation decomposition and different wing quantities on FWR are individually investigated. Additionally, computational fluid dynamics simulation is utilized as an auxiliary and supplementary approach to analyze the aerodynamic characteristics of the flapping-rotation motion. The result proves that the stable flapping-rotation motion does produce a more significant lift increase than the normal flapping motions. Under the premise of stable flapping-rotation motion, more wings will not only produce more lift but also require more driving power. The interactions between the wings also affect the flapping-rotation motion. [ABSTRACT FROM AUTHOR]

Wind energy is one of the mainstream types of renewable energy. At present, the majority of the traditional wind turbines could only make use of the near-earth wind energy. However, the high-altitude wind energy has a greater value and potential for its high stability and large storage of energy. The research of exploiting high-altitude wind energy is starting up in China while there are studies about the usage of high-altitude wind energy across the world and some are in the process of flight test. The research on the variation and development of the altitude wind energy system(AWES) is conducted which contains an analysis of crosswind mode, an introduction of typical AWES abroad in last decade, a discussion of critical points including tether, accuracy control, multifunctional ground station and comprehensive optimization as a foundation for future development and further research on this direction.