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Chinese Journal of Aeronautics 2025年第1期38卷 271-285页

作者： Tao ZHANG Xuhui ZHANG Luoyu RAO Chongguang SHI Chengxiang ZHU Yancheng YOU School of aerospace Engineering Xiamen UniversityXiamen 361005China china Academy of aerospace Science and Innovation Beijing 100176China

The primary Mach Reflection(MR)and pressure/heating loads on V-shaped Blunt Leading Edges(VBLEs)with variable elliptic cross-sections and conic crotches are theoretically investigated in this *** simplified continuity method is used to forecast the shock *** theoretical predictions and the numerical simulations for the Mach stem and the triple point as well as the curved shock accord *** on the theoretical model,an analysis of the impact of the axial ratio a/b of the cross-sectional shape and the eccentricity e of the crotch sweep path on shock structures is carried *** shock configurations obtained from the theoretical model enable the derivation of the transition boundaries between the primary MR and the same family Regular Reflection(sRR).It is found that the increase of a/b and e can both facilitate the primary MR to sRR *** resulting transition and the corresponding generation of the wall pressure and heat flux are then *** results indicate that higher values of the ratio a/b can significantly reduce the wall pressure and heating loads by inducing the primary MR to sRR ***,the increase in the eccentricity e results in increased loads,despite causing the same transition.

关键词： Aerodynamics Hypersonic flow Shock waves Heat flux V-shaped blunt leading edges

Numerical simulation for large baseline interferometric imaging altimeter

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Geodesy and Geodynamics 2025年第1期16卷 111-126页

作者： Jie Liu Bo Liu Xiaonan An Haifeng Kou Bing Li china Academy of aerospace Science and Innovation

Sea topography information holds significant importance in oceanic research and the climate change detection. Radar imaging altimetry has emerged as the leading approach for global ocean observation,employing synthetic aperture radar(SAR) interferometry to enhance the spatial resolution of Sea topography. Nevertheless, current payload capacity and satellite hardware limitations prevent the extension of the interferometric baseline by enlarging the physical antenna size. This constraint hinders achieving centimeter-level accuracy in interferometric altimetry. To address this challenge, we conducted a numerical simulation to assess the viability of a large baseline interferometric imaging altimeter(LB-IIA). By controlling the baseline within the range of 600-1000 m through spiral orbit design in two satellites and mitigating baseline de-correlation with the carrier frequency shift(CFS) technique, we aimed to overcome the above limitations. Our findings demonstrate the efficacy of the CFS technique in compensating for baseline decoherence, elevating coherence from less than 0.1 to over 0.85. Concurrently. The height difference accuracy between neighboring sea surfaces reaches 1 cm within a 1 km resolution. This study is anticipated to serve as a foundational reference for future interferometric imaging altimeter development, catering to the demand for high-precision sea topography data in accurate global bathymetry inversion.

关键词： Sea topography Numerical simulation Carrier frequency shift (CFS) Large baseline interferometric imaging altimeter (LB-IIA)

Mode-switching cooperative defense strategy for the orbit pursuit-evasion-defense game

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Defence Technology(防务技术) 2025年第2期44卷 272-286页

作者： Yongshang Wei Tianxi Liu Cheng Wei School of aerospace Harbin Institute of TechnologyHarbin150000China

This paper presents a mode-switching collaborative defense strategy for spacecraft pursuit-evasiondefense *** these scenarios,the pursuer tries to avoid the defender while capturing the evader,while the evader and defender form an alliance to prevent the pursuer from achieving its ***,the behavioral modes of the pursuer,including attack and avoidance modes,were established using differential game *** modes are then recognized by an interactive multiple model-matching algorithm(IMM),that uses several smooth variable structure filters to match the modes of the pursuer and update their probabilities in real *** on the linear-quadratic optimization theory,combined with the results of strategy identification,a two-way cooperative optimal strategy for the defender and evader is proposed,where the evader aids the defender to intercept the pursuer by performing luring *** results show that the interactive multi-model algorithm based on several smooth variable structure filters perform well in the strategy identification of the pursuer,and the cooperative defense strategy based on strategy identification has good interception performance when facing pursuers,who are able to flexibly adjust their game objectives.

关键词： Cooperative policy Differential games Orbit pursuit-evasion-defense game Mod recognition

Status analysis on sputtering and erosion evaluation methods of ion optic systems

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Chinese Journal of Aeronautics 2025年第1期38卷 254-270页

作者： Long MIAO Tongxun YANG Zhengxi ZHU Chang LU Zhiwen WU Ningfei WANG School of aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Chongqing Innovation Center Beijing Institute of TechnologyChongqing 404100China Advanced aerospace Power and Energy Research Center Beijing Institute of TechnologyZhuhai 519088China

In the past few decades,ion engines have been widely used in deep-space propulsion and satellite *** aim of extending the thruster lifetime is still one of the most important parts during the design stage of ion *** one of the core components of ion engine,the grid assembly of ion optic systems may experience long-term ion sputtering in extreme electro-thermal environments,which will eventually lead to its structural and electron-backstreaming *** this paper,the current studies of the grid assembly erosion process are systematically analyzed from the aspects of sputtering damage process of grid materials,numerical simulations,and measurements of erosion characteristics of grid *** advantages and disadvantages of various erosion prediction models are highlighted,and the key factors and processes affecting the prediction accuracy of grid assembly erosion patterns are *** different types of experimental methods of grid assembly erosion patterns are *** analysis in this paper is of great importance for selecting the sputter-resistant grid materials,as well as establishing the erosion models and measurement methods to accurately determine the erosion rate and failure modes of grid ***,the working conditions and structure parameters of ion optic systems could be optimized based on erosion models to promote the ion engine lifetime.

关键词： Electric propulsion Ion optic systems Sputtering yield Erosion characteristics Erosion pattern measurement Lifetime evaluation

Optimal condition analysis of target localization using multi-agents with uncertain positions

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Control Theory and Technology 2025年第1期23卷 131-144页

作者： Yi Hou Ning Hao Fenghua He Chen Xie Yu Yao School of aerospace Harbin Institute of TechnologyHarbin150001HeilongjiangChina

This paper delves into the problem of optimal placement conditions for a group of agents collaboratively localizing a target using range-only or bearing-only *** challenge in this study stems from the uncertainty associated with the positions of the agents,which may experience drift or disturbances during the target localization ***,we derive the Cramer-Rao lower bound(CRLB)of the target position as the primary analytical ***,we establish the necessary and sufficient conditions for the optimal placement of *** on these conditions,we analyze the maximal allowable agent position error for an expected mean squared error(MSE),providing valuable guidance for the selection of agent positioning *** analytical findings are further validated through simulation experiments.

关键词： Cramer-Rao lower bound(CRLB) Target localization Uncertain sensor position Multi-agent systems

Experimental Study on Geometry Characteristics of Turbulent Premixed Flames for Natural Gas/Air Mixtures

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Journal of Thermal Science 2025年第1期34卷 268-282页

作者： ZHENG Weilin WANG Qijiao XIAO Huahua CHEN Xiaoxiao XIE Fan ZENG Wen Liaoning Key Lab of Advanced Test Technology for aerospace Propulsion System Shenyang Aerospace UniversityShenyang 110136China State Key Laboratory of Fire Science University of science and Technology of ChinaHefei 230027China AVIC Shenyang Aircraft Design and Research Institute Shenyang 110035China

In this study,focusing on the geometry characteristics of spherical expanding flame,the turbulent premixed flames of natural gas/air mixtures were investigated in a fan-stirred turbulent *** effects of initial temperature(T=300-400 K),initial pressure(P=0.1-0.3 MPa),turbulence intensity(u'=1.0-2.7 m/s),oxygen volumetric percentage(φ(O_(2))=15%-21%)and carbon dioxide volumetric percentage(φ(CO_(2))=0-20%)were delved *** flame profile under the Cartesian coordinate system was derived from the schlieren images taken by the high-speed ***,from both macroscopic and microscopic perspectives,the influence of experimental conditions on the flame geometry characteristics was explored through flame front extraction,wavelet decomposition and network *** results demonstrate that for significant flame wrinkling,changes in species concentrations and turbulence intensity have more pronounced effects on the flame wrinkling *** wrinkling of the flame front maintains a certain degree of similarity,as evidenced by the locally concentrated distribution of the angles of the maximum fluctuation *** disturbance energy under large-scale(D6-D8)disturbances exhibits relatively high values with a similar trend,exerting a significant impact on the geometry characteristics of the flame *** peaks of correlation degree are scattered either with the decomposition scale or the development of flame radius,indicating no linear correlation between different detail ***,the probability distribution of node degrees in key wrinkled regions exhibits different trends with that of large-scale wrinkling and disturbance energy,especially with changes in initial *** occurs because the number of key wrinkles varies based on the perturbation's strength or the region's ***,an increase in the fluctuation frequency of the flame's local radius may not necessarily lead to an increase in the number of key folded regions.

关键词： geometry characteristics large-scale wrinkling wavelet decomposition network topology fan-stirred turbulent combustor

Si-C Foam Porous-Medium Combustion Power-Generation System for Low-Calorific-Value Biomass Syngas

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Journal of Thermal Science 2025年第1期34卷 206-222页

作者： YANG Jianwen CHEN Wei CAO Bingwei LIU Xinhui LI Hang College of Mechanical and aerospace Engineering Jilin UniversityChangchun 130025China School of Mechanical and Vehicle Engineering Changchun UniversityChangchun 130022China

Syngas produced from the gasification of organic feedstocks from biomass is one of the clean and sustainable sources of *** advantages of simple access and renewability of biomass energy can meet the energy needs of temporary power *** study presents a biomass power-generation system for vehicular *** biomass and a free-piston Stirling engine generator(FPSEG)as the primary material and prime mover,respectively,biomass energy is converted into electricity by combusting the syngas to heat the *** and key parameter design for biomass gasification and thermoelectric conversion systems within a power generation system were performed.A porous medium area was constructed using Si-C foam ceramics to obtain an energy-conversion experimental *** effects of bed height,porosity,porous-region diameter,and air-intake conditions on the power-generation performance were investigated,and optimisations were performed for the thermoelectric conversion *** rate of increase during FPSEG power generation first increased and then decreased with increasing bed height,peaking at a bed height of 40 *** increasing porous-region diameter accelerated FPSEG power generation,whereas porosity changes in the porous media did not significantly affect the rate of change during FPSEG power *** increasing air intake,the rate of increase during power generation first increased and then *** maximum change rate and the highest thermoelectric conversion efficiency of the power-generation system occurred at 9.5 m^(3)/h and 6.5 m^(3)/h(~45.1%)air intakes,*** the thermal inertia and combustion structure of the thermoelectric conversion system significantly increased the power-generation rate of the system,with 1.8 W/s being observed at a 9.7 m^(3)/h air intake.

关键词： biomass gasification combined heat and power(CHP) porous media combustion power generation

An asymmetrically variable wingtip anhedral angles morphing aircraft based on incremental sliding mode control:Improving lateral maneuver capability

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Chinese Journal of Aeronautics 2025年第1期38卷 455-470页

作者： Xiaodong LIU Yong XU Jianqiao LUO School of aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Chongqing Innovation Center Beijing Institute of TechnologyChongqing 401120China

This paper presents the design of an asymmetrically variable wingtip anhedral angles morphing aircraft,inspired by biomimetic mechanisms,to enhance lateral maneuver ***,we establish a lateral dynamic model considering additional forces and moments resulting during the morphing process,and convert it into a Multiple Input Multiple Output(MIMO)virtual control system by importing virtual ***,a classical dynamics inversion controller is designed for the outer-loop system.A new Global Fast Terminal Incremental Sliding Mode Controller(NDO-GFTISMC)is proposed for the inner-loop system,in which an adaptive law is implemented to weaken control surface chattering,and a Nonlinear Disturbance Observer(NDO)is integrated to compensate for unknown *** whole control system is proven semiglobally uniformly ultimately bounded based on the multi-Lyapunov function ***,we consider tracking errors and self-characteristics of actuators,a quadratic programmingbased dynamic control allocation law is designed,which allocates virtual control inputs to the asymmetrically deformed wingtip and *** dynamic models are incorporated to ensure physical realizability of designed allocation ***,comparative experimental results validate the effectiveness of the designed control system and control allocation *** NDO-GFTISMC features faster convergence,stronger robustness,and 81.25%and 75.0%reduction in maximum state tracking error under uncertainty compared to the Incremental Nonlinear Dynamic Inversion Controller based on NDO(NDO-INDI)and Incremental Sliding Mode Controller based on NDO(NDO-ISMC),*** design of the morphing aircraft significantly enhances lateral maneuver capability,maintaining a substantial control margin during lateral maneuvering,reducing the burden of the rudder surface,and effectively solving the actuator saturation problem of traditional aircraft during lateral maneuvering.

关键词： Morphing aircraft Lateral maneuver capability Incremental sliding mode control Multi-Lyapunov function method Control theory Control allocation law

Safe flight corridor constrained sequential convex programming for efficient trajectory generation of fixed-wing UAVs

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Chinese Journal of Aeronautics 2025年第1期38卷 537-550页

作者： Jing SUN Guangtong XU Zhu WANG Teng LONG Jingliang SUN School of aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Huzhou Institute Zhejiang UniversityHuzhou 313000China Department of Automation North China Electric Power University(Baoding)Baoding 071003China

Generating dynamically feasible trajectory for fixed-wing Unmanned Aerial Vehicles(UAVs)in dense obstacle environments remains computationally *** paper proposes a Safe Flight Corridor constrained Sequential Convex Programming(SFC-SCP)to improve the computation efficiency and reliability of trajectory ***-SCP combines the front-end convex polyhedron SFC construction and back-end SCP-based trajectory optimization.A Sparse A^(*)Search(SAS)driven SFC construction method is designed to efficiently generate polyhedron SFC according to the geometric relation among obstacles and collision-free *** transforming the nonconvex obstacle-avoidance constraints to linear inequality constraints,SFC can mitigate infeasibility of trajectory planning and reduce computation ***,SCP casts the nonlinear trajectory optimization subject to SFC into convex programming subproblems to decrease the problem *** addition,a convex optimizer based on interior point method is customized,where the search direction is calculated via successive elimination to further improve *** experiments on dense obstacle scenarios show that SFC-SCP can generate dynamically feasible safe trajectory *** studies with state-of-the-art SCP-based methods demonstrate the efficiency and reliability merits of ***,the customized convex optimizer outperforms off-the-shelf optimizers in terms of computation time.

关键词： Fixed-wing unmanned aerial vehicle Efficient trajectory planning Safe flight corridor Sequential convex programming Customized convex optimizer

Glacier lake outburst floods(GLOF)susceptibility in the Boqu Basin in Tibetan Plateau

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Journal of Mountain Science 2025年第2期22卷 505-520页

作者： XU Shuai SU Peidong LIANG Yu LI Yougui LONG Wei XU Mingshan School of Geoscience and Technology Southwest Petroleum UniversityChengdu 610500China Survey and Design corporation of Power china Chengdu Engineering corporation Limited Chengdu 611130China

The glacial lake in the Boqu Basin in Tibetan Plateau has changed significantly in recent years due to global warming,seriously affecting the natural and social environments in downstream *** obtained the change characteristics of glacial lakes by analyzing remote sensing images and evaluated the outburst floods susceptibility of glacial lakes in the Boqu Basin by combining fuzzy mathematics and random forest *** empirical formula for glacial lake hazard evaluation was established based on a fuzzy comprehensive *** confusion matrix were used to assess the evaluation effect of each *** conclusions were as follows:(1)Under the influence of climate warming,glaciers are retreating further from the glacial lakes,and the size of glaciers that can impact these lakes is *** conditions,such as steep slopes around the lakes,have replaced glacier tongues as the primary factors threatening the susceptibility of the glacial lakes;(2)Among the three evaluation methods,the empirical formula offers high calculation accuracy and is the most convenient to use,which provides an accuracy rate of 85.71%in susceptibility evaluation of the Boqu Basin glacial lake and can be applied to other areas in the rapid evaluation of the susceptibility of glacial lakes;(3)The impact analysis of the collapse shows that the collapse of the Galongco fault would cause large economic losses.

关键词： Glacial lake change Hazard assessment Fuzzy comprehensive evaluation Random forest