A wide-speed aircraft capable of horizontal takeoff possesses advantages of rapid response speed,high maneuverability,improved safety,and suitability for different terrains and applications.In this study,a morphing ve...A wide-speed aircraft capable of horizontal takeoff possesses advantages of rapid response speed,high maneuverability,improved safety,and suitability for different terrains and applications.In this study,a morphing vehicle design with horizontal takeoff and landing capabilities is presented.The aircraft achieves strong aerodynamic performance at subsonic to hypersonic speeds through a wave-like fuselage and a continuously variable sweep angle between 30°and 60°.First,the configuration of the vehicle and its morphing mechanism are described.Then,through numerical modeling,the aerodynamic performance of the vehicle is investigated over a flight profile progressing from horizontal takeoff to hypersonic cruising.These results indicate that different vehicle configurations might be used for different speed ranges so as to optimize performance.The numerical and flow field data also suggest that the effect of the variable sweep angle on the aerodynamic characteristics is weaker in the hypersonic speed range compared to the subsonic range.Overall,the proposed morphing aircraft has excellent aerodynamic characteristics in the speed range of Mach 0.3 to Mach 7.Moreover,its lift coefficients and lift-to-drag ratios in the subsonic phase ensure that horizontal takeoff and landing can be achieved,and its variable sweep angle effectively extends the flight envelope.展开更多
To tackle the instability fault diagnosis challenges in wide-speed-range supersonic inlets,this study proposes an inlet fault decision fusion diagnosis algorithm based on attention mechanism feature fusion,achieving e...To tackle the instability fault diagnosis challenges in wide-speed-range supersonic inlets,this study proposes an inlet fault decision fusion diagnosis algorithm based on attention mechanism feature fusion,achieving efficient diagnosis of instability faults across wide-speed regimes.First,considering the requirement for wall pressure data extraction in mathematical modeling of wide-speed-range inlets,a supersonic inlet reference model is established for computational fluid dynamics(CFD)simulations.Second,leveraging data-driven modeling techniques and support vector machine(SVM)algorithms,a high-precision mathematical model covering wide-speed domains and incorporating instability mechanisms is rapidly developed using CFD-derived inlet wall pressure data.Subsequently,an inlet fault decision fusion diagnosis method is proposed.Pressure features are fused via attention mechanisms,followed by Dempster-Shafer(D-S)evidence theory-based decision fusion,which integrates advantages of multiple intelligent algorithms to overcome the limitations of single-signal diagnosis methods(low accuracy and constrained optimization potential).The simulation results demonstrate the effectiveness of the data-driven wide-speed-range inlet model in achieving high precision and rapid convergence.In addition,the fusion diagnosis algorithm has been shown to attain over 95%accuracy in the detection of instability,indicating an improvement of more than 5%compared to the accuracy of other single fault diagnosis algorithms.This enhancement effectively eliminates the occurrence of missed or false diagnoses,while demonstrates robust performance under operational uncertainties.展开更多
基金supported by the National Natural Science Foundation of China(No.62173274).
文摘A wide-speed aircraft capable of horizontal takeoff possesses advantages of rapid response speed,high maneuverability,improved safety,and suitability for different terrains and applications.In this study,a morphing vehicle design with horizontal takeoff and landing capabilities is presented.The aircraft achieves strong aerodynamic performance at subsonic to hypersonic speeds through a wave-like fuselage and a continuously variable sweep angle between 30°and 60°.First,the configuration of the vehicle and its morphing mechanism are described.Then,through numerical modeling,the aerodynamic performance of the vehicle is investigated over a flight profile progressing from horizontal takeoff to hypersonic cruising.These results indicate that different vehicle configurations might be used for different speed ranges so as to optimize performance.The numerical and flow field data also suggest that the effect of the variable sweep angle on the aerodynamic characteristics is weaker in the hypersonic speed range compared to the subsonic range.Overall,the proposed morphing aircraft has excellent aerodynamic characteristics in the speed range of Mach 0.3 to Mach 7.Moreover,its lift coefficients and lift-to-drag ratios in the subsonic phase ensure that horizontal takeoff and landing can be achieved,and its variable sweep angle effectively extends the flight envelope.
基金supported by the Na tional Natural Science Foundation of China(No.62373185)the National Key R&D Program of China(No.2023YFB3307100).
文摘To tackle the instability fault diagnosis challenges in wide-speed-range supersonic inlets,this study proposes an inlet fault decision fusion diagnosis algorithm based on attention mechanism feature fusion,achieving efficient diagnosis of instability faults across wide-speed regimes.First,considering the requirement for wall pressure data extraction in mathematical modeling of wide-speed-range inlets,a supersonic inlet reference model is established for computational fluid dynamics(CFD)simulations.Second,leveraging data-driven modeling techniques and support vector machine(SVM)algorithms,a high-precision mathematical model covering wide-speed domains and incorporating instability mechanisms is rapidly developed using CFD-derived inlet wall pressure data.Subsequently,an inlet fault decision fusion diagnosis method is proposed.Pressure features are fused via attention mechanisms,followed by Dempster-Shafer(D-S)evidence theory-based decision fusion,which integrates advantages of multiple intelligent algorithms to overcome the limitations of single-signal diagnosis methods(low accuracy and constrained optimization potential).The simulation results demonstrate the effectiveness of the data-driven wide-speed-range inlet model in achieving high precision and rapid convergence.In addition,the fusion diagnosis algorithm has been shown to attain over 95%accuracy in the detection of instability,indicating an improvement of more than 5%compared to the accuracy of other single fault diagnosis algorithms.This enhancement effectively eliminates the occurrence of missed or false diagnoses,while demonstrates robust performance under operational uncertainties.
