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Journal of Thermal Science 2018年第1期27卷 89-94页

作者： S.Natarajan K.Pitchandi N.V.Mahalakshmi Department of Mechanical engineering Sri Venkateswara College of EngineeringSriperumbudur-602117TamilnaduIndia. Department of Mechanical engineering Sri Venkatcswara College of EngineeringSriperumbudur-602117TamilnaduIndia. internal combustion engineering Division Department of Mechanical EngineeringCollege of EngineeringAnna UniversityChennai-600025TamilnaduIndia.

The performance and emission characteristics of a PPCCI engine fuelled with ethanol and diesel blends were car- ded out on a single cylinder air cooled CI engine. In order to achieve the optimal process response with a limited number of experimental cycles, multi objective grey relational analysis had been applied for solving a multiple response optimization problem. Using grey relational grade and signal-to-noise ratio as a performance index, a combination of input parameters was prefigured so as to achieve optimum response characteristics. It was observed that 20% premixed ratio of blend was most suitable for use in a PPCCI engine without significantly affecting the engine performance and emissions characteristics.

关键词： PPCCI Biodiesel Optimization Grey-Taguchi method

Three-dimensional Simulation of Gas/Solid Flow in Spout-fluid Beds with Kinetic Theory of Granular Flow

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Chinese Journal of Chemical engineering 2006年第5期14卷 611-617页

作者：钟文琪章名耀金保升袁竹林 Education Ministry Key Laboratory on Clean Coal Power Generation and combustion Technology Thermoenergy Engineering Research Institute Southeast University

A three-dimensional Eulerian multiphase model, with closure law according to the kinetic theory of granular flow, was used to study the gas/solid flow behaviors in spout-fluid beds. The influences of the coefficient of restitution due to non-ideal particle collisions on the simulated results were tested. It is demonstrated that the simulated result is strongly affected by the coefficient of restitution. Comparison of simulations with experiments in a small spout-fluid bed showed that an appropriate coefficient of restitution of 0.93 was necessary to simulate the flow characteristics in an underdesigned large size of spout-fluid bed coal gasifier with diameter of lm and height of 6m. The internal jet and gas/solid flow patterns at different operating conditions were obtained. The simulations show that an optimal gas/solid flow pattern for coal gasification is found when the spouting gas flow rate is equal to the fluidizing gas flow rate and the total of them is two and a half times the minimum fluidizing gas flow rate. Besides, the radial distributions of particle velocity and gas velocity show similar tendencies; the radial distributions of particle phase pressure due to particle collisions and the particle pseudo-temperature corresponding to the macroscopic kinetic energy of the random particle motion also show similar tendencies. These indicate that both gas drag force and particle collisions dominate the movement of particles.

关键词： gas/solid flow CFD Eulerian multiphase model kinetic theory of granular flow spout-fluid bed

Numerical Analysis of the Thermal Behavior of a Hermetic Reciprocating Compressor

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Journal of Earth Science and engineering 2017年第1期7卷 1-9页

作者： Stefan Posch Johann Hopfgartner Erwin Berger Bemhard Zuber Lukas Dtir Stefan Stangl Raimund Almbauer institute of internal combustion engines and Thermodynamics Graz University of Technology Inffeldgasse 19 8010 Graz Austria Secop Austria GmbH Jahnstraβe 30 8280 Furstenfeld Austria

A numerical model to predict the temperature field in a hermetic reciprocating compressor for household refrigeration appliances is presented in this work. The model combines a high resolution three-dimensional heat conduction formulation of the compressor＇s solid parts, a three-dimensional CFD （computational fluid dynamics） approach for the gas line domain and lumped formulations of the shell gas and the lubrication oil. Heat transfer coefficients are determined by applying CFD to the gas line side and correlations from the literature on the shell gas and oil side, respectively. The valve in the gas line simulation is modelled as a parallel moving fiat plate. By means of an iterative loop the temperature field of the solid parts acts as boundary condition for the CFD calculation of the gas line which returns a cycle averaged quantity of heat to the solid parts. Using an iteration method which is based on the temperature deviation between two iteration steps, the total number of iterations and consequently the computational time can be reduced. The loop is continued until a steady-state temperature field is obtained. Calculated temperatures of the solid parts are verified by temperature measurements of a calorimeter test bench.

关键词： Compressor simulation CFD.

Experimental and Numerical Research on Deformation Behavior of Thin-Walled and Large Expansion Ratio Guide Vane Liner in Hydroforming Process

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Journal of Harbin institute of Technology(New Series) 2015年第4期22卷 1-9页

作者： Pengzhi Cheng Lihui Lang Yulong Ge Shangwen Ruan Xinmin Duan Tianwei Shao School of Mechanical engineering & Automation Beihang University AVIC Shenyang Liming Aero-engine (Group) Co. Ltd.

Some tube hydroforming process tests and further research work were conducted to manufacture hollow guide vane liners( made of super alloy GH3030).The relative thickness( t0/ OD) of the tubular blank is approximately 0. 01,and the maximum expansion ratio( Dmax/ OD) of the needed part is more than 40%,and the length to diameter ratio of the expansion regionis more than 3. 0. It is very hard to manufacture this kind of ultra-thin-wall,curved axis and large expansion ratio tubular part without fracture and wrinkles. The success of the process is highly dependent on useful wrinkles with appropriate internal pressure and axial feeding. A simplified finite element model and a theoretical model are used for detecting the deformation behavior and forming laws. Further study results demonstrate that the useful wrinkles do not appear at the same time and middle-wrinkles need bigger axial force than tube-end-wrinkles and feeding-wrinkles. The wrinkles can transfer bigger axial force after its wave peak has come into contact with the die inner surface. The thickness thinning rate of the element at the peak is bigger than that at the trough. With the increase of the axial and hoop stress ratio,the critical buckling stress also increases. Microstructure examination results show that the grain size in the maximum thinning zone has been stretched and refined after the large deformation and annealing *** process is feasible and the finished part is qualified.

关键词： tube hydroforming super alloy ultra-thin-wall large expansion ratio useful wrinkle plastic buckling critical buckling stress

Surface evolution of Al-Si-Cu alloy in thermal shock under different heating speeds

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Journal of Central South University 2021年第10期28卷 2988-2998页

作者： LIU Lei ZHANG Hai-jun LI Bo-yan YANG Zhong BAO Tong LI Jian-ping GUO Yong-chun XIA Feng YANGWei LI Hai-ying School of Materials and Chemical engineering Xi'an Technological UniversityXi'an 710021China China North engine Research institute(Tianjin) Tianjin 300400China

In order to understand the initial surface damage of Al piston in unsteady thermal environment like knock combustion,T6 heat treated cast Al-Si-Cu alloy was thermal shocked under different heating speeds between room temperature and 450°C by adjusting the environmental *** surface evolution was mainly characterized in view of roughness,hardness,morphology,texture,phase and element *** indicated that both the roughness and hardness went up to the maximum and then decreased with rising heating ***-structure and phase analysis suggested that the interactions of solid phase transition and oxidation with enhancing thermal stress took responsible for the surface evolution.

关键词： Al alloy piston thermal shock heating speed surface roughness

Parametric Modeling System for Cooling Turbine Blade Based on Feature Design

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Transactions of Nanjing University of Aeronautics and Astronautics 2020年第5期37卷 758-767页

作者： WANG Jie ZHAO Miaodong MAO Jianxing Aero engine Academy of China Beijing 101300P.R.China School of Energy and Power engineering Beihang UniversityBeijing 100191P.R.China Aero-engine Research institute Beihang UniversityBeijing 100191P.R.China Beijing Key Laboratory of Aero-engine Structure and Strength Beijing 100191P.R.China

Based on feature modeling and mathematical analysis methods,a process-oriented and modular parametric design system for advanced turbine cooling blade is developed with UG API,aiming at the structural complexity and high design difficulty of aero-engine cooling turbine *** relationship between the external and internal body features,the body attached feature is analyzed as viewed from the feature and parameter *** parametric design processes and design examples of the external body shape,tenon,platform and internal body shape,ribs,pin fins are *** system improves the design efficiency of cooling turbine blade and establishes the foundation of multidisciplinary design optimization procedure for it.

关键词： parametric modeling cooling turbine blade UG API

Research on Measurements for Temperature and Stress of Pistons in internal combustion engine

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Defence Technology（防务技术） 2008年第2期4卷 81-84页

作者：董小瑞谭建松 Department of Vehicle and Power engineering North University of China China North engine Research institute

In both numerical simulation and experimental research for the piston of internal combustion engine, the verification foundations are always insufficient. The reason is the measurements for its transient temperature and stress under actual operation conditions are very difficult. A multi-channel measurement-storage technology is used in the engine bench experiment to measure the piston temperature and stress in real time. The temperature and stress changes in the engine operation process are obtained. They provide reliable instructive criteria for numerical analysis and experiment of the piston working state.

关键词：大功率机械测量与储存温度应力内燃机

An integrated turbocharger design approach to improve engine performance

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Science China(Technological Sciences) 2010年第1期53卷 69-74页

作者： ZHANG YangJun1,CHEN Tao1,ZHUGE WeiLin1,ZHANG ShuYong2 & XU JianZhong3 1 State Key Laboratory of Automotive Safety and Energy,Tsinghua University,Beijing 100084,China 2 National Key Laboratory of Diesel engine Turbocharging Technology,P.O.B.22,Datong 037036,China 3 institute of engineering Thermophysics,Chinese Academy of Sciences,Beijing 100190,China 1. State Key Laboratory of Automotive Safety and Energy Tsinghua University Beijing 100084 China2. National Key Laboratory of Diesel Engine Turbocharging Technology P.O.B. 22 Datong 037036 China3. Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing 100190 China

Turbocharging technology is today considered as a promising way for internal combustion engine energy saving and CO2 *** design is a major challenge for turbocharged engine performance *** turbocharger designer must draw upon the information of engine operation conditions,and an appropriate link between the engine requirements and design features must be carefully developed to generate the most suitable design *** objective of this research is to develop a turbocharger design approach for better turbocharger matching to an internal combustion *** development of the approach is based on the concept of turbocharger design and interaction links between engine cycle requirements and design parameter values.A turbocharger through flow model is then used to generate the design *** integrated method has been applied with success to a gasoline engine turbocharger assembly.

关键词： turbocharger design internal combustion engine integrated method through flow model

Electrochemical impedance spectroscopy of PEM fuel cells at low hydrogen partial pressures: efficient cell tests for mass production

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Industrial Chemistry & Materials

Industrial Chemistry & Materials 2024年第1期2卷 132-140页

作者： Felix Haimerl Sunil Kumar Michael Heere Aliaksandr S.Bandarenka Technical University of Munich School of Natural SciencesDepartment of PhysicsProfessorship of Physics of Energy Conversion and Storage85748 GarchingGermany BMW AG Petuelring 13080809 MunchenGermany Technical University Braunschweig Faculty of Mechanical EngineeringInstitute of Internal Combustion Engines and Fuel Cells38108 BraunschweigGermany Technical University of Munich Catalysis Research Center TUMErnst-OttoFischer-Straße 185748 GarchingGermany

Quality testing costs hinder the large-scale production of PEM fuel cell systems due to long testing times and high safety measures for *** eliminating both issues,electrochemical impedance spectroscopy at low hydrogen concentrations can provide valuable insights into fuel cell ***,the influence of high anode stream dilutions on PEM fuel cell performance is not yet completely *** study presents a new equivalent circuit model to analyze impedance spectra at low hydrogen partial *** proposed model accurately describes the impedance response and explains the performance decrease at low hydrogen ***,the reduced availability of hydrogen at the anode leads to rising reaction losses from the hydrogen ***,the resulting losses lead to potential changes also influencing the cathode *** findings indicate that impedance spectroscopy at low hydrogen partial pressure might provide a reliable fuel cell quality control tool,simplifying production processes,reducing costs,and mitigating risks in fuel cell production.

关键词： PEM fuel cells Electrochemical impedance spectroscopy EIS Large scale PEMFC production Anodes Cathodes

Tailored wrinkles for tunable sensing performance by stereolithography

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Interdisciplinary Materials 2024年第3期3卷 414-424页

作者： Ruiyi Jiang Jie Pu Yuxuan Wang Jipeng Chen Gangwen Fu Xue Chen Jiayu Yang Jianghua Shen Xing Sun Jun Ding Xi Xu Key Laboratory of Flexible Electronics of Zhejiang Province Ningbo Institute of Northwestern Polytechnical UniversityNingboChina Frontiers Science Center for Flexible Electronics Institute of Flexible ElectronicsNorthwestern Polytechnical UniversityXi'anChina Research&Development Institute of Northwestern Polytechnical University in ShenzhenNanshan DistrictShenzhenChina Affiliated Hospital of Nanjing University of Chinese Medicine NanjingChina School of Aeronautics Northwestern Polytechnical UniversityXi'anChina combustion Internal Flow and Thermal-Structure LaboratorySchool of AstronauticsNorthwestern Polytechnical UniversityXi'anChina Department of Materials Science and engineering Faculty of EngineeringNational University of SingaporeSingapore

Conducting polymer hydrogel can address the challenges of stricken biocompatibility and ***,conventional conducting polymer hydrogels are often brittle and weak due to the intrinsic quality of the material,which exhibits *** property may cause a delay in sensor response time due to *** overcome these limitations,we have designed a wrinkle morphology three-dimensional(3D)substrate using digital light processing technology and then followed by in situ polymerization to form interpenetrating polymer network *** novel design results in a wrinkle morphology conducting polymer hydrogel elastomer with high precision and geometric freedom,as the size of the wrinkles can be controlled by adjusting the treating *** wrinkle morphology on the conducting polymer hydrogel effectively reduces its viscoelasticity,leading to samples with quick response time,low hysteresis,stable cyclic performance,and remarkable resistance ***,the 3D gradient structure augmented the sensor's sensitivity under minimal stress while exhibiting consistent sensing *** properties indicate the potential of the conducting polymer hydrogel as a flexible sensor.

关键词： 3D printing conducting polymer hydrogel flexible sensor micro-wrinkle structure