To explore the application potential of the Hybrid Wing Body (HWB) configuration in the field of large cargo aircraft, an optimization design method balancing aerodynamic efficiency and dynamic stability is proposed. Taking the lift-to-drag ratio and the Dutch roll mode flight quality during the cruise phase as optimization objectives, an aerodynamic/stability optimization framework is constructed. An Euler equation solver with boundary layer corrections is employed for rapid analysis, while a high-fidelity RANS solver is used to validate the optimization results. Based on the analysis of the initial configuration, the optimization framework is applied to enhance the aerodynamic efficiency and dynamic stability modal response characteristics of the target configuration. RANS calculation results show that, under the premise of maintaining design constraints, the total drag coefficient of the aerodynamically optimized configuration is reduced by approximately 3.5 counts, with the cruise lift-to-drag ratio increasing from 21.244 to 21.784, achieving an efficiency improvement of approximately 2.54%. For the configuration optimized with both aerodynamic performance and dynamic stability objectives, the total drag coefficient is reduced by approximately 2.4 counts, the cruise lift-to-drag ratio is improved to 21.609 with an efficiency increase of approximately 1.72%, and the product of the Dutch roll mode damping ratio and the undamped natural frequency is increased from 0.02633 to 0.05117. This improvement elevates the flight quality from Level 3 to Level 2 according to the MIL-F-8785C standard, significantly enhancing the lateral-directional dynamic stability. The optimization framework effectively balances aerodynamic performance and dynamic stability, providing insights and references for the engineering application and optimization of HWB-configured large cargo aircraft.

Supersonic civil aircraft have become one of the important directions for the future development of civil aviation. For the rapid conceptual design and performance optimization of supersonic civil aircraft layouts, an aerodynamic optimization framework for transonic and supersonic dual-cruise regimes was developed using a medium-fidelity solver based on the Euler equations with boundary layer correction to ensure computational efficiency while capturing key flow features. Using this framework, the baseline configuration was optimized, and the optimization results were selected from the Pareto optimal solution set in the dual-speed domain. Building on this, a high-precision low-drag adjoint optimization based on RANS equation for the wing-body combination was carried out under supersonic conditions, resulting in drag reductions of 43.4 counts at Ma = 0.9 and 54.1 counts at Ma = 1.8. To further address the multidisciplinary design challenge of simultaneously minimizing both drag and sonic boom intensity, a prediction method combining ray tracing technique and augmented Burgers equation was employed to simulate the propagation of near-field sonic boom signals. The ground waveforms were analyzed using the Mark VII criteria developed by Stevens to calculate the perceived loudness in decibel (PLdB) of the sonic boom. A multidisciplinary optimization framework considering both aerodynamic performance and sonic boom signals at different azimuthal angles was established to achieve a low-drag and low-sonic boom design. The optimization results showed that, compared to the baseline configuration, the final shape achieved comprehensive improvements in both drag and sonic boom performance throughout the entire sonic boom carpet region: The drag coefficient was reduced by 30.6 counts at Ma = 0.9 and by 50.3 counts at Ma = 1.8, while the average ground-level perceived loudness in decibel was reduced by 4.84 PLdB.

A 2% scale, cruising version of a 450-seat class Blended-Wing-Body (BWB) transport was tested in the China Aerodynamic Research and Development Center’s FL-26 2.4-by-2.4-meter subsonic wind tunnel. The focus of the wind tunnel test was to investigate the aerodynamic performance of the latest BWB transport design, which would also aid in choosing a final engine arrangement in the three most potential engine integration layouts. The wind tunnel model can be tested with and without the nacelle and has three sets of different nacelle/tail integration positions. Computational Fluid Dynamics (CFD) simulations were performed in engine-aircraft integration design to find appropriate nacelle installing parameters of each layout. The comparison of CFD with experimental results shows good agreement. Wind tunnel measurements indicate that the tail-mounted engine layout produces the minimum drag penalty, while the fuselage-mounted engine layout increases drag the most. Experimental pressure measurement illustrates the effect of nacelle integration on the wing-body surface pressure distribution. This experimental and numerical research provides a reference for future BWB Propulsion-Airframe Integration (PAI) design.