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Hypersonic shock wave and turbulent boundary layer interaction in a sharp cone/flare model

Chinese Journal of Aeronautics 2023年第3期36卷 80-95页

作者： Fulin TONG Junyi DUAN Jiang LAI Dong SUN Xianxu YUAN State Key Laboratory of Aerodynamics China Aerodynamics Research and Development CenterMianyang 621000China Computational Aerodynamics Institute China Aerodynamics Research and Development CenterMianyang 621000China LHD Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China

A direct numerical simulation of hypersonic Shock wave and Turbulent Boundary Layer Interaction(STBLI)at Mach 6.0 on a sharp ***-angle circular cone/flare configuration at zero angle of attack is *** flare angle is *** the momentum thickness Reynolds number based on the incoming turbulent boundary layer on the sharp circular cone is Re θ=*** is found that the mean flow is separated and the separation bubble occurring near the corner exhibits *** Reynolds analogy factor changes dramatically across the interaction,and varies between 1.06 and 1.27 in the downstream region,while the QP85 scaling factor has a nearly constant value of 0.5 across the *** evolution of the reattached boundary layer is characterized in terms of the mean profiles,the Reynolds stress components,the anisotropy tensor and the turbulence kinetic *** is argued that the recovery is incomplete and the near-wall asymptotic behavior does not occur for the hypersonic *** addition,mean skin friction decomposition in an axisymmetric turbulent boundary layer is carried out for the first *** of the interaction,the contributions of transverse curvature and body divergence are negligible,whereas the positive contribution associated with the turbulence kinetic energy production and the negative spatial-growth contribution are *** on scale decomposition,the positive contribution is further divided into terms with different spanwise length *** negative contribution is analyzed by comparing the convective term,the streamwise-heterogeneity term and the pressure gradient term.

关键词： Shock wave Hypersonic turbulent boundary layer Heat transfer Skin friction decomposition Direct numerical simulation

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A Bibliometric Analysis of Different Machine Translation Evaluation Metrics 5

A Bibliometric Analysis of Different Machine Translation Eva...

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5th International Conference on Intelligent Communication Technologies and Virtual Mobile Networks, ICICV 2024

作者： Kaur, Kiranjeet Chauhan, Shweta University Centre for Research & Development Department of Computer Science and Engineering Chandigarh University Gharuan Punjab Mohali140413 India University Centre for Research & Development Chandigarh University Gharuan Punjab Mohali140413 India

ISBN: (纸本)9798350385649

Machine Translation (MT) systems mechanically represent a source language into a destination language while maintaining the originality of context using various Natural Language Processing approaches. The need to assess the translation quality produced by machine translation systems has grown as a result of their increased use. However, due to their complicated morphology and syntax, other low-resource languages might not always be appropriate for or applicable to the existing evaluation measures intended for English and other languages. The technique of evaluating machine translation is known as machine translation evaluation (MTE). In MTE, the amount of similarity and accuracy is determined by contrasting the output produced by the machine translation with the reference translation. The study assesses the metrics on several translation systems using datasets for low-resource languages. The paper advances the field of machine translation (MT) by illuminating appropriate evaluation criteria for low-resource languages. For this research. data from the Scopus database were gathered and analyzed using the keywords 'machine translation' AND 'evaluation metrics' from 1993 to 2023. Using Scopus databases, this article computes numerous application areas, documents published yearly, and keyword occurrences analysis. This work provides analysis and support for the significance of evaluation measures for different low-resource languages. © 2024 IEEE.

关键词： Machine translation

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research advances and hotspot evolution of carbon fiber composite material recycling based on bibliometrics analysis

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Carbon research 2025年第1期4卷 1-20页

作者： Guo, Xiang Li, Tian Liu, Chunting Wu, Mengying Liao, Yuyan Xu, Jinwu Chen, Weijing Pei, Linlin Liu, Fang Chen, Da Science and Technology Innovation Research Institute Civil Aviation University of China Tianjin300300 China Tianjin Engineering Research Center of Civil Aviation Energy-Environment and Green Development Tianjin300300 China School of Transportation Science and Engineering Civil Aviation University of China Tianjin300300 China Agro-Environmental Protection Institute Ministry of Agriculture and Rural Affairs Tianjin300191 China

The rapid application and development of high-performance carbon fiber composite material brought challenges for the recovery of composite waste. Recycling of carbon fiber composites has been particularly demanded. The bibliometric method combined with S-shaped curves and visualization tools VOSviewer and CiteSpace were applied to quantitatively analyze 5979 research papers related to carbon fiber recycling in the Web of science database from 2000 to 2023. The bibliometric results show that the number of research papers related to carbon fiber recycling has increased from 23 in 2000 to 1247 in 2023. The S-shaped curve of post volume indicates that carbon fiber recovery has great potential for development in the next 20 years. In the global research on carbon fiber recycling technology, China ranks first in terms of publication volume, and the United States ranks second. Both are core countries in the international cooperation network. The evolution of keywords and hotspots indicates that the hotspots in the field of carbon fiber recycling are gradually moving towards "sustainable", and "circular economy". Based on patent analysis, the field of carbon fiber recycling is currently experiencing accelerated growth and will become a hot research topic in the future. There are various recycling technologies for carbon fiber composite materials, with pyrolysis as the mainstream. Mechanical recycling causes significant performance loss, while chemical methods are limited by cost. In the future, recycling technologies will focus on improving fiber performance and reducing environmental impact. © The Author(s) 2025.

关键词： Zero-carbon

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Data-Driven Design for Targeted Regulation of Heat Transfer in Carbon/Carbon Composite Structure

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Journal of Thermal science 2024年第2期33卷 648-657页

作者： XIAO Heye WANG Zelin WANG Hui JI Ritian Unmanned System Research Institute Northwestern Polytechnical UniversityXi’an710072China School of Aeronautics Northwestern Polytechnical UniversityXi’an710072China Research&Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen518063China MOE Key Laboratory of Thermo-Fluid Science and Engineering School of Energy and Power EngineeringXi’an Jiaotong UniversityXi’an710049China

Targeted regulation of heat transfer in carbon/carbon composite structure is built for cooling electronic device.A three-dimensional data-driven design model coupling genetic algorithm(GA) with self-adaption deep learning for targeted regulation of heat transfer in built structure is *** self-adaption deep learning model predicts the temperature of built structure closer to optimal value in GA *** distributions of pore and carbon fiber bundles in built structure are optimized by the proposed *** surface temperature of electronic device in the optimized structures is 19.1%-27.5% lower than that in the initial configurations when the porosity of built structure varies from 3% to 11%.The surface temperature of electronic device increases with an increase in *** built structure with carbon fiber bundles near the surface of electronic device and pore distribution in the middle of structure has a higher heat dissipation capacity compared with that in the initial ***,the computation time of the proposed model is less than one tenth compared with that of the traditional genetic algorithm.

关键词： targeted regulation of heat transfer self-adaption deep learning genetic algorithm carbon/carbon composite structure

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Combined anisotropic and cyclic constitutive model for laser powder bed fusion fabricated aluminum alloy

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Chinese Journal of Aeronautics 2025年第1期38卷 165-184页

作者： Fei-Fan LI Jihong ZHU Weihong ZHANG Shifeng WEN Jingwen SONG Jun MA Gang FANG State IJR Center of Aerospace Design and Additive Manufacturing School of Mechanical EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Research&Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen 518063China School of Materials Science and Engineering Northwestern Polytechnical UniversityXi'an 710072China Department of Mechanical and Industrial Engineering Norwegian University of Science and TechnologyTrondheim 7491Norway State Key Laboratory of Tribology in Advanced Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China

This study presents new methods to effectively model the anisotropic yielding and hardening behavior of laser powder bed fusion fabricated aluminum alloy under both monotonic and cyclic loading *** proposed model combines the yield surface-interpolation method to accurately describe the anisotropic hardening rates in various directions,with the Chaboche kinematic hardening rule to precisely reflect the cyclic *** numerical implementation of the combined anisotropic and cyclic constitutive model,a fully implicit stress integration algorithm based on return mapping method is ***,the multiple parameters associated with the model are categorized and identified in an uncoupled *** isotropic and cyclic hardening parameters are determined by an inverse method,and the stability of the optimization outcomes is validated by applying different starting points for the ***,the back-stress effect on the identification of anisotropic parameters associated with the stress invariant-based Hill48 yield function is considered for the first *** consideration leads to an improved prediction accuracy compared to the identification of anisotropic parameters without considering back-stress *** combined anisotropic and cyclic constitutive model,along with the calibrated parameters,are proven capable of accurately reproducing the intricate deformation behavior of laser powder bed fusion fabricated AlSi10Mg.

关键词： Constitutive models Anisotropy Kinematic hardening Laser powder bed fusion Aluminum alloys

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Accurately predicting hypersonic transitional flow on cone via a symmetry approach

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Chinese Journal of Aeronautics 2023年第7期36卷 337-347页

作者： Weitao BI Kexin ZHENG Zhou WEI Zhensu SHE State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Engineering Science College of EngineeringPeking UniversityBeijing 100871China State Key Laboratory of Aerodynamics and Computational Aerodynamics Institute China Aerodynamics Research and Development CenterMianyang 621000China

A new algebraic transition model is proposed based on a Structural Ensemble Dynamics(SED)theory of wall turbulence,for accurately predicting the hypersonic flow heat transfer on *** model defines the eddy viscosity in terms of a two-dimensional multi-regime distribution of a Stress Length(SL)function,and hence is named as *** paper presents clear evidence of precise predictions of transition onset location and peak heat flux of a wide range of hypersonic Transitional Boundary Layers(TrBL)around straight cone at zero incidence,to an unprecedented accuracy as validated by over 70 measurements for varying five crucial influential factors(Mach number,temperature ratio,cone half angle,nose Reynolds number and noise level).The results demonstrate the universality of the postulated multi-regime similarity structure,in characterizing not only the spatial non-uniform distribution of the eddy viscosity in hypersonic TrBL on cone,but also the dependence of the transition onset location on the five influential *** latter yields a novel correlation formula for transition center Reynolds number which takes similar functional form as the SL function within the symmetry *** is concluded that the SED-SL model simulates TrBL around cone with uniformly high accuracy,and then points out to an optimistic alternative way to construct hypersonic transition model.

关键词： Cones Heat flux Hypersonic boundary layers Transition flow Turbulence models

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Mechanoluminescent-Triboelectric Bimodal Sensors for Self-Powered Sensing and Intelligent Control

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Nano-Micro Letters 2023年第5期15卷 313-325页

作者： Bo Zhou Jize Liu Xin Huang Xiaoyan Qiu Xin Yang Hong Shao Changyu Tang Xinxing Zhang State Key Laboratory of Polymer Materials Engineering Polymer Research InstituteSichuan UniversityChengdu 610065People’s Republic of China Chengdu Development Center of Science and Technology China Academy of Engineering PhysicsChengdu 610200People’s Republic of China

Self-powered flexible devices with skin-like multiple sensing ability have attracted great attentions due to their broad applications in the Internet of Things(IoT).Various methods have been proposed to enhance mechano-optic or electric performance of the flexible devices;however,it remains challenging to realize the display and accurate recognition of motion trajectories for intelligent ***,we present a fully self-powered mechanoluminescent-triboelectric bimodal sensor based on micronanostructured mechanoluminescent elastomer,which can patterned-display the force *** deformable liquid metals used as stretchable electrode make the stress transfer stable through overall device to achieve outstanding mechanoluminescence(with a gray value of 107 under a stimulus force as low as 0.3 N and more than 2000 cycles reproducibility).Moreover,a microstructured surface is constructed which endows the resulted composite with significantly improved triboelectric performances(voltage increases from 8 to 24 V).Based on the excellent bimodal sensing performances and durability of the obtained composite,a highly reliable intelligent control system by machine learning has been developed for controlling trolley,providing an approach for advanced visual interaction devices and smart wearable electronics in the future IoT era.

关键词： Bimodal sensors Mechanoluminescence Triboelectric nanogenerator Intelligent control Self-powered

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Beaver pond identification from multi-temporal and multi-sourced remote sensing data

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地球空间信息科学学报（英文版） 2024年第4期27卷 953-967页

作者： Wen Zhang Baoxin Hu Glen Brown Shawn Meyer Department of Earth and Space Science and Engineering York UniversityTorontoONCanada Wildlife Research and Monitoring Section Ontario Ministry of Northern DevelopmentMinesNatural Resources & ForestryPeterboroughONCanada Canadian Wildlife Service Environment and Climate Change CanadaOttawaONCanada

The maintenance and restoration of wetland habitat is a priority conservation action for most waterfowl and other wetland-dependent species in North *** much progress in targeting habitat management in staging and wintering areas,methods to identify and target high-quality breeding habitats that result in the greatest potential for wildlife are still *** is particularly true for species that breed in remote,inaccessible areas such as the American black duck,an intensively managed game bird in Eastern North *** evidence suggests that black ducks prefer productive,nutrient-rich waterbodies,such as beaver ponds,information about the distribution and quality of these habitats across the vast boreal forest is lacking with accurate identification remaining a *** advancements in remote sensing technologies that provide spatially extensive and temporally repeated information are particularly useful in meeting this information *** this study,we used multi-source remotely sensed information and a fuzzy analytical hierarchy process to map the spatial distribution of beaver ponds in *** use of multi-source data,including a Digital Elevation Model,a Sentinel-2 Multi-Spectral Image,and RadarSat 2 Polarimetric data,enabled us to identify individual beaver ponds on the *** model correctly identified an average of 83.0％of the known beaver dams and 72.5％of the known beaver ponds based on validation with an independent *** study demonstrates that remote sensing is an effective approach for identifying beaver-modified wetland features and can be applied to map these and other wetland habitat features of interest across large spatial ***,the systematic acquisition strategy of the remote sensors employed is well suited for monitor-ing changes in wetland conditions that affect the availability of habitats important to waterfowl and other wildlife.

关键词： Remote sensing American black duck wetland beaver pond Sentinel-2 RadarSat Fuzzy Analytical Hierarchy Process

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Selective core-shell doping enabling high performance 4.6 V-LiCoO_(2)

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Journal of Energy Chemistry 2024年第8期95卷 684-693,I0015页

作者： Yueming Xia Jianrui Feng Jinhui Li Yan Li Zhengfeng Zhang Xiaoqi Wang Jianli Shao Manling Sui Pengfei Yan Beijing Key Laboratory of Microstructure and Property of Solids College of Materials Science&EngineeringBeijing University of TechnologyBeijing 100124China PetroChina Research Institute of Petroleum Exploration&Development Beijing 100083China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

Constructing robust surface and bulk structure is the prerequisite for realizing high performance high voltage LiCoO_(2)(LCO).Herein,we manage to synthesize a surface Mg-doping and bulk Al-doping coreshell structured LCO,which demonstrates excellent cycling ***-cell shows 94.2%capacity retention after 100 cycles at 3.0-4.6 V(***/Li^(+))cycling,and no capacity decay after 300 cycles for fullcell test(3.0-4.55 V).Based on comprehensive microanalysis and theoretical calculations,the degradation mechanisms and doping effects are systematically *** the undoped LCO,high voltage cycling induces severe interfacial and bulk degradations,where cracks,stripe defects,fatigue H2 phase,and spinel phase are identified in grain *** the doped LCO,Mg-doped surface shell can suppress the interfacial degradations,which not only stabilizes the surface structure by forming a thin rock-salt layer but also significantly improves the electronic conductivity,thus enabling superior rate *** Al-doping can suppress the lattice"breathing"effect and the detrimental H3 to H1-3 phase transition,which minimizes the internal strain and defects growth,maintaining the layered structure after prolonged *** theoretical calculations,this work deepens our understanding of the doping effects of Mg and Al,which is valuable in guiding the future material design of high voltage LCO.

关键词： Lithium-ion battery Doping effect Failure mechanism High-voltage LiCoO_(2) Electron microscopy

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Experimental Study on Mixed-Mode(Ⅰ–Ⅱ)Fracture Toughness of Freshwater Ice

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Acta Mechanica Solida Sinica 2024年第2期37卷 252-264页

作者： Yaozhong Xu Mao Zhou Xian Yi Wen Hua Jiuzhou Huang Wenyu Zhang Shiming Dong Key Laboratory of Deep Underground Science and Engineering Ministry of EducationCollege of Architecture and EnvironmentSichuan UniversityChengdu610065China Failure Mechanics and Engineering Disaster Prevention Key Laboratory of Sichuan Province Sichuan UniversityChengdu610065China China Aerodynamics Research and Development Center/Low Speed Aerodynamics Research Institute Mianyang621000China College of Mechanical and Electrical Engineering Xichang UniversityXichang615000China

In recent years,the issue of aircraft icing has gained widespread *** breaking and detachment of dynamic ice can pose a threat to flight ***,the shedding and fracture mechanisms of dynamic ice are unclear and cannot meet the engineering needs of ice-shedding hazard ***,studying the fracture toughness of ice bodies has extremely important practical *** address this issue,this article uses a centrally cracked Brazilian disk(CCBD)specimen to measure the pure modeⅠtoughness and pure modeⅡfracture toughness of freshwater ice at different loading *** mixed-mode(Ⅰ–Ⅱ)fracture characteristics of ice are discussed,and the experimental results are compared and analyzed with the theoretical values of the generalized maximum tangential stress(GMTS)criterion considering the influence of *** results indicated that as the loading rate increases,the pure modeⅠtoughness and pure modeⅡfracture toughness of freshwater ice decrease,and the fracture toughness of freshwater ice is more sensitive to the loading rate.Ⅰn terms of fracture criteria,the theoretical value of the ratio of pure modeⅡfracture toughness to pure modeⅠfracture toughness based on the GMTS criterion is in good agreement with the experimental value,while the theoretical value based on the maximum tangential stress(MTS)criterion deviates significantly from the experimental value,indicating that the GMTS criterion considering the influence of T-stress can better predict the experimental results.

关键词： Freshwater ice Fracture criteria Centrally cracked Brazilian disk(CCBD) Mixed-mode(Ⅰ-Ⅱ) Loading rate

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