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Design method of optimal control schedule for the adaptive cycle engine steady-state performance

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Chinese Journal of Aeronautics 2022年第4期35卷 148-164页

作者： Yihao XU hailong tang Min CHEN School of Energy and Power Engineering Beihang UniversityBeijing 100083China Research Institute of Aero-Engine Beihang UniversityBeijing 102206China

The alternative working modes and flexible working states are the outstanding features of an adaptive cycle engine, with a proper control schedule design being the only way to exploit the performance of such an engine. However, unreasonable design in the control schedule causes not only performance deterioration but also serious aerodynamic stability problems. Thus, in this work,a hybrid optimization method that automatically chooses the working modes and identifies the optimal and smooth control schedules is proposed, by combining the differential evolution algorithm and the Latin hypercube sampling method. The control schedule architecture does not only optimize the engine steady-state performance under different working modes but also solves the control-schedule discontinuity problem, especially during mode transition. The optimal control schedules are continuous and almost monotonic, and hence are strongly suitable for a control system, and are designed for two different working conditions, i.e., supersonic and subsonic throttling,which proves that the proposed hybrid method applies to various working conditions. The evaluation demonstrates that the proposed control method optimizes the engine performance, the surge margin of the compression components, and the range of the thrust during throttling.

关键词： Adaptive cycle engine Control schedule design Hybrid optimization method Mode transition Performance optimization

Matching mechanism analysis on an adaptive cycle engine

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Chinese Journal of Aeronautics 2017年第2期30卷 706-718页

作者： Zheng Junchao Chen Min tang hailong School of Energy and Power Engineering Beihang University Beijing 100083 China

As a novel aero-engine concept,adaptive cycle aero-engines（ACEs） are attracting wide attention in the international aviation industry due to their potential superior task adaptability along a wide flight ***,this superior task adaptability can only be demonstrated through proper combined engine control schedule *** has resulted in an urgent need to investigate the effect of each variable geometry modulation on engine performance and ***,the aim of this paper is to predict and discuss the effect of each variable geometry modulation on the matching relationship between engine components as well as the overall engine performance at different operating modes,on the basis of a newly developed nonlinear component-based ACE performance *** show that at all four working modes,turning down the high pressure compressor variable stator vane,the low pressure turbine variable nozzle,the nozzle throat area,and turning up the core-driven fan stage variable stator vane,the high pressure turbine variable nozzle can increase the thrust at the expense of a higher high pressure turbine inlet total ***,the influences of these adjustments on the trends of various engine components＇ working points and working lines as well as the ratio of the rotation speed difference are different from each *** above results provide valuable guidance and advice for engine combined control schedule design.

关键词： Adaptive cycle engine Matching relationship Matching mechanism Performance Variable geometries

A multi-fidelity simulation method research on front variable area bypass injector of an adaptive cycle engine

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Chinese Journal of Aeronautics 2022年第4期35卷 202-219页

作者： Zhewen XU Ming LI hailong tang Min CHEN School of Energy and Power Engineering Beihang UniversityBeijing 100083China Aero Engine Academy of China Beijing 101300China Research Institute of Aero-Engine Beihang UniversityBeijing 102206China

Front Variable Area Bypass Injector(Front-VABI) is a component of the Adaptive Cycle Engine(ACE) with important variable-cycle features. The performance of Front-VABI has a direct impact on the performance and stability of ACE, but the current ACE performance model uses approximate models for Front-VABI performance calculation. In this work, a multi-fidelity simulation based on a de-coupled method is developed which delivers a more accurate calculation of the Front-VABI performance based on Computational Fluid Dynamics(CFD) simulation. This simulation method proposes a form of Front-VABI characteristic and its matching calculation method between it and the ACE performance model, constructs a coupling method between the(2-D) Front-VABI model and the(0-D) ACE performance model. The result shows, when ACE works in triple bypass mode, the approximate model cannot account for the effect of FrontVABI pressure loss on Core Driven Fan Stage(CDFS) design pressure ratio, and the calculated error of high-pressure turbine inlet total temperature is more than 40 K in mode transition condition(the transition operating condition between triple bypass mode and double bypass mode). In double bypass mode, the approximate model can better simulate the performance of FrontVABI by considering the local loss of area expansion. This method can be applied to the performance-optimized design of Front-VABI and the ACE control law design during mode transition.

关键词： Adaptive cycle engine Computational fluid dynamics Front variable area bypass injector Multi-fidelity simulation Performance model

A versatile volume-based modeling technique of distributed local quadratic convergence for aeroengines

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Propulsion and Power Research 2024年第1期13卷 46-63页

作者： Yudong Liu Min Chen hailong tang School of Energy and Power Engineering Beihang UniversityBeijing 100191China Research Institute of Aero-Engine Beihang UniversityBeijing 100191China

For advanced aero-engine design and research,modeling and simulation in a digital environment is indispensable,especially for engines of complicated configurations,such as var-iable cycle engines(VCE)and adaptive cycle engines(ACE).Also,in the research of future smart engines,reliable real-time digital twins are ***,the 2 dominant methods that used in solving the simulation models,Newton-Raphson(N-R)method and volume-based method,are not fully qualified for the study requirements,because neither of them reaches the satisfactory balance of convergence rate and calculating *** this study,by deeply analyzing the mathematical principle of these 2 methods,a novel modeling and solving method for aero-engine simulation,which integrates the advantages of both N-R and volume-based methods,is *** has distributed architecture and local quadratic convergence *** a novel modeling method for variable area bypass injectors(VABI)is put *** facilitate simulation of various configurations of *** modeling cases,including a high bypass-ratio(BPR)turbofan and an ACE,illustrate that the novel technique decreases the iterations by about two-thirds comparing with volume-based method,while the success rate of convergence remains over 99%.This proves its superiority in both convergence and calculating efficiency over the conventional *** technique can be used in advanced gas turbine en-gine design and control strategy optimization,and study of digital twins.

关键词： Aero-engine performance simulation Variable cycle engine Variable area bypass injector Digital twin Newton-Raphson method

Simple Vanilla Derivatives for Long-Lived Room-Temperature Polymer Phosphorescence as Invisible Security Inks

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Research 2021年第1期2021卷 496-506页

作者： Yongfeng Zhang Zhonghao Wang Yan Su Yan Zheng Wenji tang Chaolong Yang hailong tang Lunjun Qu Youbing Li Yanli Zhao School of Materials Science and Engineering Chongqing University of TechnologyChongqing 400054China Division of Chemistry and Biological Chemistry School of Physical and Mathematical SciencesNanyang Technological University21 Nanyang LinkSingapore 637371

Developing novel long-lived room-temperature polymer phosphorescence(RTPP)materials could significantly expand their application ***,a series of RTPP materials based on eight simple vanilla derivatives for security ink application are *** to strong mutual hydrogen bonding with polyvinyl alcohol(PVA)matrix,vanilla-doped PVA films exhibit ultralong phosphorescence emission under ambient conditions observed by naked eyes,where methyl vanillate shows the longest emission time up to 7 ***,when vanilla-doped PVA materials are utilized as invisible security inks,and the inks not only present excellent luminescent emission stability under ambient conditions but also maintain perfect reversibility between room temperature and 65℃ for multiple *** to the unique RTPP performance,an advanced anticounterfeiting data encoding/reading strategy based on handwriting technology and complex pattern steganography is developed.

关键词： ambient mutual maintain

Goal Programming for Stable Mode Transition in Tandem Turbo-ramjet Engines

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Chinese Journal of Aeronautics 2009年第5期22卷 486-492页

作者： Chen Min tang hailong Zhu Zhili School of Jet Propulsion Beijing University of Aeronautics and Astronautics Beijing 100191 China

This article, in order to guarantee the stable mode transition in tandem turbo-ramjet engines, investigates the multi-objective and multi-variable goal programming algorithm. First, it introduces the structural features of the variable cycle turbo-ramjet engines, the principles of selecting the mode transition operation point and the design parameters, and the characteristics of the turbofan mode and the ramjet mode. Second, a component-based variable cycle turbo-ramjet engine model is developed to simulate the mode transition process. Third, the Newton-Raphson algorithm is used to solve the multi-variable and multi-objective optimization problem. The results show that with the maximum residua of only 0.06%, this algorithm has an acceptable convergence that meets the predetermined goals. Finally, the simulation shows that the stable turbo-ramjet mode transition could be realized with the mode transition control law developed by the algorithm.

关键词： propulsion transition goal programming algorithm turbine-based combine cycle engine turbofan engine ramjetengine hypersonic

Time-series surface water reconstruction method(TSWR)based on spatial distance relationship of multi-stage water boundaries

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International Journal of Digital Earth 2022年第1期15卷 2335-2354页

作者： Mingyang Li Shanlong Lu Cong Du Yong Wang Chun Fang Xinru Li hailong tang Muhammad Hasan Ali Baig Harrison Odion Ikhumhen International Research Center of Big Data for Sustainable Development Goals Key Laboratory of Digital Earth ScienceAerospace Information Research InstituteChinese Academy of SciencesBeijingPeople’s Republic of China College of Resources and Environment University of Chinese Academy of SciencesBeijingPeople’s Republic of China School of Earth Sciences and Spatial Information Engineering Hunan University of Science and TechnologyXiangtanPeople’s Republic of China School of Geospatial Engineering and Science Sun Yat-Sen UniversityZhuhaiPeople’s Republic of China Institute of Geo-Information & Earth-Observation (IGEO) PMAS Arid Agriculture University RawalpindiRawalpindiPakistan Key Laboratory of Ministry of Education for Coastal Wetland Ecosystems College of the Environment and EcologyXiamen UniversityXiamenPeople’s Republic of China

Spatiotemporal continuity of surface water datasets widely known for its significance in the surface water dynamic monitoring and assessments,are faced with drawbacks like cloud influence,which hinders the direct extraction of data from time-series remote sensing *** study proposes a Time-series Surface Water Reconstruction method(TSWR).The initial stage of this method involves the effective use of remote sensing images to automatically construct multi-stage surface water boundaries based on Google Earth Engine(GEE).Then,we reconstructed regions the reconstruction of regions with missing water pixels using the distance relationship between the multi-stage water boundaries in previous and later *** applied to 10 large rivers around the world,this method yielded an overall accuracy of 98%for water extraction,an RMSE of 0.41 ***,time-series reconstruction tests conducted in 2020 on the Lancang and Danube rivers revealed a significant improvement in the image *** findings demonstrated that this method could not only be used to accurately reconstruct the surface water distribution missing water images,but also to depict a more pronounced time variation *** successful application of this method on GEE demonstrates its importance for use on large scales or in global studies.

关键词： Google earth engine sentinel-2 surface water reconstruction time-series surface water data

Nitrogen-doped TiO_(2)/Graphene Composites Synthesized via the Vapour-thermal Method

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Journal of Wuhan University of Technology(Materials Science) 2022年第6期37卷 1105-1113页

作者： tang hailong WANG Min JU tangtong DAI Yue WANG Meiling MA Yongqing ZHENG Ganhong School of Materials Science and Engineering Anhui UniversityHefei 230039China School of Physics and Optoelectronic Engineering Anhui UniversityHefei 230039China Institute of Physical Science and Information Technology Anhui UniversityHefei 230039China

TiO_(2)/graphene composite was synthesized in the vapor environment of *** order to improve the properties of composite,N-doped of TiO_(2)/graphene with different N/Ti molar ratio was prepared in the vapor environment of deionized water and used urea as the source of *** N-doped occupies in the interstitial sites of TiO_(2) lattice,substitutes for O element in TiO_(2) and for C element in graphene,and simultaneously changes the chemical states of Ti and O elements in TiO_(2).N-doped changes the morphology of TiO_(2) from nano-sheets to nanoparticles,accompanying with the decrease in specific surface area of the composites,first increases the particle size of TiO_(2) and then decreases,and alters the vibration modes of *** composite with RN/Ti=2 exhibits the enhanced photocatalytic degradation performance to methylene blue,and the degradation rate increases from 7.7×10^(−2) min^(−1) for the undoped composite to 9.6×10^(−2) min^(−1).

关键词： TiO_(2)/graphene vapor-thermal nitrogen-doped photocatalytic performance

Some Critical Issues in the Development of Chinese High-Speed Rail: Challenges and Coping Strategies

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Journal of Transportation Technologies 2014年第2期4卷 164-174页

作者： Min Chen hailong tang Kun Zhang School of Energy and Power Engineering BeiHang University Beijing China

In this paper, several critical issues related to Chinese high-speed rails (CHSR) are analyzed, investigated and discussed, including development background, reasons for high ticket fare, some typical factors that influence the environmental life-cycle assessment, time and cost comparison of typical door-to-door travel routes between different transport modes and complementary strategies among different transport modes. First, the results show that the expanding high-speed rail network increased the pressure on the country's roads in the 2010 spring festival rush period due to the high ticket fare of CHSR. Second, due to lower than expected ridership because of the high ticket price and limited demand in less developed areas, some Chinese CHSR projects have become economically unsustainable. Third, without sufficient ridership and service life, the utilization of HSR was unable to show any advantages in the environmental impact compared with the other transport modes. In addition, the impact of shock from CHSR on Chinese domestic civil airlines is evident when the travel distance is below 1050 km. The key objective of the investigation is to enhance our understanding of the development and operation of Chinese high-speed rail. One of the key contributions of the current paper is the presented suggestions for complementary strategies between different transport modes to make full use of Chinese transportation resources to promote low carbon economy.

关键词： Chinese High-Speed Rails Development Cost Time Environmental Life-Cycle Assessment Strategies