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numerical Investigation into the Transient Behavior of the Spike-Type Rotating Stall for a Transonic Compressor Rotor

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Fluid Dynamics & Materials Processing 2022年第3期18卷 761-773页

作者： Pengfei Ju Fangfei Ning Zhiting Tong Jingying Wang Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical EngineeringTianjin University of TechnologyTianjin300384China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education(Tianjin University of Technology) Tianjin300384China Research Institute of Aero-Engine Beihang UniversityBeijing100191China National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics School of Energy and Power EngineeringBeihang UniversityBeijing100191China School of Energy and Power Engineering Shandong UniversityJinan250061China Shandong Engineering Laboratory for High-Efficiency Energy Conservation and Energy Storage Technology&Equipment Shandong UniversityJinan250061China

In this paper,a numerical investigation into a spike-type rotating stall process is carried out considering a transonic compressor rotor(the NASA Rotor 37).Through solution of the Unsteady Reynolds-Averaged Navier-Stokes(URANS)equations,the evolution process from an initially circumferentially-symmetric near-stall flow field to a stable stall condition is simulated without adding any artificial *** the near-stall operating point,periodic fluctuations are present in the overall flow of the ***,the blockage region in the channel periodically shifts from middle span to the *** fluctuating condition does not directly lead to stall,while the full-annulus calculation eventually evolves to ***,a kind of“early disturbance”feature appears in the dynamic signals,which propagates forward ahead of the rotor.

关键词： Transonic compressor spike stall numerical simulation early disturbance dynamic signal

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Effect of Catalyst Shapes on Hydrogen Production from Exhaust Gas-Fuel Reforming for Ng Engine: A Mesoscale 3d Simulation

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SSRN 2023年

作者： Xu, Wenxin Zhang, Zunhua Huang, Yong Qian, Hang Li, Gesheng School of Naval Architecture Ocean and Energy Power Engineering Wuhan University of Technology Hubei Wuhan430063 China National Engineering Research Center of Ship & Shipping Control System Hubei Wuhan430063 China

Since the catalyst packed in the reformer is the main factor affecting internal flow heat transfer and reforming reaction process, the realization of Reformed Exhaust Gas Recirculation (REGR) technology mainly lies in the exhaust gas-fuel reformer. In the present study, the geometry and calculation models of a fixed-bed packed with different types of particles were constructed by Computational Fluid Dynamics (CFD) and Blender software to investigate the effects of particle shapes and initial conditions, including the exhaust temperature, volume ratio of methane to oxygen (i.e., M/O), volume ratio of steam to methane (i.e., S/M), gas hourly space velocity (i.e., GHSV), etc., on the performance of fluid, heat transfer and reaction flow in the process of exhaust-methane reforming. Six particle shapes viz. sphere as the reference, 1-hole sphere, cylinder, Raschig ring, trilobe and 4-hole cylinder were chosen. The accuracy of random packing model was verified by combining the empirical formula of porosity distribution and experimental data. The results showed that the shape of catalyst has a noticeable effect on the flow resistance and uniformity of the flow field in the random packing area. Among the particle shapes considered in the present work, the fixed-bed packed with 1-hole spheres is the optimal option for the exhaust reformer, which offers the highest methane conversion, hydrogen yield per unit pressure drop and the most uniform flow field. Moreover, the peak of the hydrogen yield, reaching 24.4%, occurs at M/O of 2 and GHSV of 8000 h-1. Besides, under different M/O, the methane conversion increases with S/M. The volume ratio of hydrogen to carbon monoxide decreases continuously with the increase of GHSV. © 2023, The Authors. All rights reserved.

关键词： Spheres

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Hydrogen Production from an On-Board Reformer for a Natural Gas Engine: A Thermodynamics Study

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SSRN 2023年

作者： Zheng, Yingyi Huang, Yong Zhang, Zunhua Long, Yanxiang Li, Gesheng Zhang, Yi School of Naval Architecture Ocean and Energy Power Engineering Wuhan University of Technology Hubei Wuhan430063 China National Engineering Research Center of ship & shipping Control System Wuhan University of Technology Hubei Wuhan430063 China

In the present study, a thermodynamic model used to simulate exhaust gas-fuel reforming process of reformer is established by equilibrium constants and demonstrated by experimental data. The effect of engine loads and excess air ratio (λ) as well as reformer feedstock on maximum theoretical reforming characteristics are investigated. Meanwhile, the energetic distribution in open-loop system of NG engine and exhaust gas-fuel reformer can be clarified by the first law of thermodynamic. The results show that the theoretical H2 production, H2 yield and CH4 conversion increase with engine loads. Under 75% engine load, maximum theoretical H2 yield reaches up to approximately 42.3% when λ = 1.4, CH4/O2 (M/O) = 1.5 and H2O/CH4 (S/M) = 2. The M/O should be maintained above 1.5 to reduce heat loss and acquire optimal reforming energy efficiency. Summarily, optimal operation conditions for reformer are confirmed: M/O = 1.5-2.5 and S/M = 1.5-2 at 75% engine load. © 2023, The Authors. All rights reserved.

关键词： Gases

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Scheduling optimization of silicon single crystal production process based on adaptive improved particle swarm optimization

Scheduling optimization of silicon single crystal production...

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2021 China Automation Congress, CAC 2021

作者： Kang, Lu Liu, Ding Wu, Yali Ping, Guozheng School of Automation and Information Engineering Xi'an University of Technology National and Local Joint Engineering Research Center of Crystal Growth Equipment and System Integration Shaanxi Key Laboratory of Complex System Control and Intelligent Information Processing Xi'an710048 China School of Automation and Information Engineering Xi'an University of Technology National and Local Joint Engineering Research Center of Crystal Growth Xi'an University of Technology Shaanxi Key Laboratory of Complex System Control and Intelligent Information Processing Xi'an710048 China School of Automation and Information Engineering Xi'an University of Technology Shaanxi Key Laboratory of Complex System Control and Intelligent Information Processing Xi'an710048 China

ISBN: (纸本)9781665426473

Aiming at the potential safety hazards of silicon single crystal production enterprises in the process of multi-furnace silicon single crystal production, and considering the maximum power load requirements in actual enterprises, a silicon single crystal production process scheduling model with the goal of minimizing the maximum completion time was established. Based on this model, an adaptive improved particle swarm optimization algorithm (Adaptive GPSO) is proposed to solve it. The algorithm retains the individual optimal value and global optimal value of the particle swarm algorithm, and introduces the crossover operation and mutation operation in the genetic algorithm to improve the new individual generation mechanism. At the same time, it performs dynamic iterative calculations on the mutation probability and crossover probability to avoid the algorithm fall into the local optimum, and improve the diversity and convergence of the algorithm. By solving different scales scheduling problems of silicon single crystal production process, the experiments on real-world data shows that the feasibility and effectiveness of the proposed algorithm. © 2021 IEEE

关键词： Genetic algorithms

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Frequency-Domain Adaptive Parametric Model Order Reduction Method for Oscillatory Stability Analysis on Multi-Converter-Fed systems

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Journal of Modern Power systems and Clean Energy 2024年第3期13卷 802-814页

作者： Xun Jiang Meiqin Mao Liuchen Chang Bao Xie Haijiao Wang Nikos D. Hatziargyriou Research Center for Photovoltaic System Engineering of Ministry of Education Hefei University of Technology Hefei China University of New Brunswick Fredericton New Brunswick Canada State Key Laboratory of Operation and Control of Renewable Energy & Storage Systems (China Electric Power Research Institute) Beijing China National Technical University of Athens Athens Greece

The oscillatory stability analysis of multi-converter-fed systems (MCFSs) with modest computational resources needs a precise parametric reduced-order impedance model (PROIM). However, the traditional Krylov subspace based parametric model order reduction (KS-PMOR) method has difficulty in building precise PROIM for MCFSs. This is because the factors related to the errors of PROIM are complicated and coupled. To fill this gap, the factors associated with the accuracy of the KS-PMOR method are estimated by defining three indicators: the convergence error, cumulative error, and rank of projection matrix. Using the three indicators, a frequency-domain adaptive parametric model order reduction (FDA-PMOR) method is developed to form the precise PROIM of MCFSs for the accurate and fast oscillatory stability analysis. The accuracy of the obtained PROIM using the proposed FDA-PMOR method and its efficiency in actual oscillatory stability analysis are validated by three MCFSs with different scales, i. e., a small-scale MCFS with four paralleled converter-based renewable energy generators (CREGs), a real-time simulation-based MCFS with eighteen paralleled CREGs, and a larger MCFS with ninety paralleled CREGs.

关键词： Impedance Power system stability Interpolation Computational modeling Reduced order systems Parametric statistics Accuracy Frequency-domain analysis Adaptation models Vectors

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Bridging the structure gap between pellets in artificial dissolution media and in gastro-intestinal tract in rats

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Acta Pharmaceutica Sinica B 2022年第1期12卷 326-338页

作者： Hongyu Sun Siyu He Li Wu Zeying Cao Xian Sun Mingwei Xu Shan Lu Mingdi Xu Baoming Ning Huimin Sun Tiqiao Xiao Peter York Xu Xu Xianzhen Yin Jiwen Zhang School of Chemical and Environmental Engineering Shanghai Institute of TechnologyShanghai 201418China Center for Drug Delivery System Shanghai Institute of Materia MedicaChinese Academy of SciencesShanghai 201210China University of Chinese Academy of Sciences Beijing 100049China School of Materials Science and Engineering Center for Supramolecular Chemistry and CatalysisDepartment of ChemistryShanghai UniversityShanghai 200444China NMPA Key Laboratory for Quality Research and Evaluation of Pharmaceutical Excipients National Institutes for Food and Drug ControlBeijing 100050China National Institutes for Food and Drug Control Beijing 100050China Shanghai Synchrotron Radiation Facility/Zhangjiang Lab Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China Center for MOST and Image Fusion Analysis Shanghai Institute of Materia MedicaChinese Academy of SciencesShanghai 201210China

Changes in structure of oral solid dosage forms(OSDF) elementally determine the drug release and its therapeutic *** this research,synchrotron radiation X-ray micro-computed tomography was utilized to visualize the 3 D structure of enteric coated pellets recovered from the gastrointestinal tract of *** structures of pellets in solid state and in vitro compendium media were *** in vivo underwent morphological and structural changes which differed significantly from those in vitro compendium ***,optimizations of the dissolution media were performed to mimic the appropriate in vivo conditions by introducing pepsin and glass microspheres in *** sphericity,pellet volume,pore volume and porosity of the in vivo esomeprazole magnesium pellets in stomach for2 h were recorded 0.47,1.55 × 10^(8)μm^(3),0.44 × 10^(8)μm^(3)and 27.6%,*** adding pepsin and glass microspheres,the above parameters in vitro reached to 0.44,1.64 × 10^(8)μm^(3)0.38 × 10^(8)μm^(3)and 23.0%,*** magnesium pellets behaved *** structural features of pellets between in vitro media and in vivo condition were bridged successfully in terms of 3 D structures to ensure better design,characterization and quality control of advanced OSDF.

关键词： Internal 3D structure 3D reconstruction Structural parameter Enteric coated pellets Synchrotron radiation X-ray micro computed tomography In vivo and in vitro structure correlation Esomeprazole magnesium Omeprazole magnesium

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洋流干扰下无人船限制水域直线跟踪安全视距制导

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哈尔滨工程大学学报（英文版） 2023年第3期22卷 602-613页

作者：彭周华李建众韩冰古楠 School of Marine Electrical Engineering Dalian Maritime UniversityDalian 116026China Dalian Key Laboratory of Swarm Control and Electrical Technology for Intelligent Ships Dalian 116026China Shanghai Ship and Shipping Research Institute Co.Ltd. Shanghai 200135China National Engineering Research Center of Ship&Shipping Control System Shanghai 200135China

The collision-free straight-line following of an unmanned surface vehicle(USV)moving in a constrained water region subject to stationary and moving obstacles is addressed in this *** systems are normally subjected to surge velocity constraints,yaw rate constraints,and unknown ocean ***,a safety-certificated line-of-sight(LOS)guidance method is proposed to achieve a constrained straight-line following ***,an antidisturbance LOS guidance law is designed based on the LOS guidance scheme and an extended state ***,collision avoidance with waterway boundaries and stationary/moving obstacles is encoded in control barrier functions,utilizing which the safety constraints are transformed into input ***,safety-certificated guidance signals are obtained by solving a quadratic programming problem subject to input *** the proposed safety-certified LOS guidance method,the USV can accomplish a straight-line following task with guaranteed input-to-state *** results substantiate the efficacy of the proposed safety-certificated LOS guidance method for the straight-line following of USVs moving in a constrained water region subject to unknown ocean currents.

关键词： Line-of-sight guidance Constrained water region Unmanned surface vehicle control barrier function Extended state observer

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A Stochastic Reachable Set Trajectory Prediction Modeling Method for Following Operation of Urban Rail Trains

A Stochastic Reachable Set Trajectory Prediction Modeling Me...

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International Conference on Intelligent Transportation

作者： Min Yang Jidong Lv Zhengwei Luo Hongjie Liu Ming Chai Lei Zhang National Engineering Research Center of Rail Transportation Operation and Control System Beijing Jiaotong University Beijing China Traffic Control Technology Co. Ltd Beijing China School of Electronic and Information Engineering Beijing Jiaotong University Beijing China

Trajectory prediction of the preceding train is a vital problem in the following operation scenario of urban rail train. However, due to the existence of sensor error and communication delay, uncertainty of trains makes it great challenge to predict train trajectory accurately. To overcome the problem, a stochastic reachable set modeling method is proposed to predict the motion trajectory associated with additional probabilistic information of the preceding train, such as position and speed etc. The main idea is to achieve a complete representation of the uncertain behavior of the train, and to improve the computational efficiency by abstracting stochastic reachable sets into extended Markov chains. Two typical validation cases demonstrate the completeness of the proposed modeling method in representing train following behaviors, thus indicating its credibility in trajectory prediction.

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Fault Diagnosis of On-board Equipment in CTCS-3 Based on CNN-LSTM Model

Fault Diagnosis of On-board Equipment in CTCS-3 Based on CNN...

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Chinese Automation Congress (CAC)

作者： Daqian Zhang Yuan Cao Miao Zhang Ming Chai Jidong Lv National Engineering Research Center of Rail Transportation Operation and Control System Beijing Jiaotong University Beijing China National Research Center of Railway Intelligence Transportation System Engineering Technology China Academy of Railway Sciences Corporation Limited Beijing China

Data-driven methods based on deep learning have achieved remarkable results of fault diagnosis of train control system due to their superiority in feature extraction. However, it still faces uneven data distribution problem, which afects the detection accuracy of fault diagnosis. In this paper, by considering different failures both in system and subsystem level of train control system, we propose a novel two-stages fault diagnosis method based on a combination of Convolutional Neural Network (CNN) and Long Short-Term Memory Network (LSTM). Firstly, samples are obtained by segmenting and vectorizing the text form faulty data set, and fed into the proposed CNN-LSTM model. Then, in the first stage, the features of the processed data are extracted through the CNN layer, whereas the correlation between the sample data are derived through the LSTM layer. Thus, the classification of first-level faults, respect as system level, are realized with high accuracy of diagnosis. Finally, in the second stage, to solve the problem of data imbalance, we reconsider part of data from the CNN layer, and put them into the new LSTM layer for secondary faults diagnosis. We apply this method on a real CTCS-3 On-board equipment and the experimental results show that the accuracy rate of our proposed model reaches 96.7% and the accuracy of small data faults is also higher when compare with other neural network models,such as TextCNN, ANN, LSTM and RNN.

关键词： Fault diagnosis Deep learning Recurrent neural networks Feature extraction control systems Data models Convolutional neural networks

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Insights into chemoautotrophic traits of a prevalent bacterial phylum CSP1-3, herein Sysuimicrobiota

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national Science Review 2024年第11期11卷 61-75页

作者： Lan Liu Zheng-Han Lian Ai-Ping Lv Nimaichand Salam Jian-Chao Zhang Meng-Meng Li Wei-Min Sun Sha Tan Zhen-Hao Luo Lei Gao Yang Yuan Yu-Zhen Ming Yu-Ting Ou Yang Yu-Xian Li Ze-Tao Liu Chao-Jian Hu Ying Chen Zheng-Shuang Hua Wen-Sheng Shu Brian P.Hedlund Wen-Jun Li Jian-Yu Jiao State Key Laboratory of Biocontrol Guangdong Provincial Key Laboratory of Plant Stress Biology and Southern Marine Science and Engineering Guangdong Laboratory ZhuhaiSchool of Life Sciences Sun Yat-Sen University National Agri-Food Biotechnology Institute School of Earth System Science Institute of Surface-Earth System Science Tianjin University National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and ManagementInstitute of Eco-Environmental and Soil SciencesGuangdong Academy of Sciences State Key Laboratory of Desert and Oasis Ecology Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands Xinjiang Institute of Ecology and GeographyChinese Academy of Sciences Chinese Academy of Sciences Key Laboratory of Urban Pollutant Conversion Department of Environmental Science and EngineeringUniversity of Science and Technology of China Institute of Ecological Science Guangzhou Key Laboratory of Subtropical Biodiversity and BiomonitoringGuangdong Provincial Key Laboratory of Biotechnology for Plant DevelopmentSchool of Life Sciences South China Normal University Guangdong Provincial Key Laboratory of Chemical Pollution South China Normal University School of Life Sciences University of Nevada Las Vegas Nevada Institute of Personalized Medicine University of Nevada Las Vegas

Candidate bacterial phylum CSP1-3 has not been cultivated and is poorly understood. Here, we analyzed 112 CSP1-3 metagenome-assembled genomes and showed they are likely facultative anaerobes, with 3 of 5 families encoding autotrophy through the reductive glycine pathway(RGP), Wood–Ljungdahl pathway(WLP) or Calvin-Benson-Bassham(CBB), with hydrogen or sulfide as electron donors. Chemoautotrophic enrichments from hot spring sediments and fluorescence in situ hybridization revealed enrichment of six CSP1-3 genera, and both transcribed genes and DNA-stable isotope probing were consistent with proposed chemoautotrophic metabolisms. Ancestral state reconstructions showed that the ancestors of phylum CSP1-3 may have been acetogens that were autotrophic via the RGP, whereas the WLP and CBB were acquired by horizontal gene transfer. Our results reveal that CSP1-3 is a widely distributed phylum with the potential to contribute to the cycling of carbon, sulfur and nitrogen. The name Sysuimicrobiota phy. nov. is proposed.

关键词： Sysuimicrobiota phy. nov facultative anaerobes chemoautotrophic metabolisms

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