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Effects of Exhaust Gas Recirculation on the Homogeneous Charge Combustion Process of n-Heptane at Different Load Conditions

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Transactions of Tianjin University 2005年第4期11卷 262-267页

作者：刘德新冯洪庆郑进才 MILLER David L CERNANSKY Nicholas P State Key Laboratory of Engines School of Mechanical Engineering Tianjin University Tianjin 300072 China Department of mechanical engineering Drexel University Philadelphia PA19104-2875 USA

Effects of exhaust gas recirculation （EGR） on homogeneous charge combustion of n-heptane was studied through simulation and experiment. Experiments were carried out in a single cylinder, four-stroke, air cooled engine and a single cylinder, two-stroke, water cooled engine. In the four-stroke engine, experiments of the effects of EGR were examined using heated N2 addition as a surrogate for external EGR and modifying engine to increase internal EGR. The ignition timing was sensitive to EGR due to thermal and chemical effects. EGR or extra air is a key factor in eliminating knock during mid-load conditions. For higher load operation the only way to avoid knock is to control reaction timing through the use of spark ignition. Experimental and modeling results from the two-stroke engine show that auto-ignition can be avoided by increasing the engine speed. The two-stroke engine experiments indicate that high levels of internal EGR can enable spark ignition at lean conditions. At higher load conditions, increasing the engine speed is an effective method to control transition from homogeneous charge compression ignition （HCCI） operation to non-HCCI operation and successful spark ignition of a highly dilute mixture can avoid serious knock.

关键词： homogeneous charge combustion exhaust gas recirculation n-heptane auto-ignition

Effect of Mg on microstructures and properties of Al-Mg-Si-Cu aluminium alloys for automotive body sheets

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中国有色金属学会会刊：英文版 2005年第1期15卷 30-34页

作者：刘宏宋文举赵刚刘春明左良 school of Materials and Metallurgy Northeastern University Shenyang 110004 China school of mechanical and Electrical engineering Shangdong Insitute of Light Industry Ji'nan 250100 China

The effects of variation of Mg content on microstructures, the tensile properties and the formability of Al-Mg-Si-Cu alloys for automotive body sheets were investigated by means of scan electron microscopy, optical metallographic analysis, tensile and Ericsson tests. The results show that for Al-Mg-Si-Cu aluminium alloys with excessive Si, with an increment of Mg content, the strength enhances, the specific elongation and Erisson values of alloys decrease, and the number of Mg2Si constituent increases and that of Al（MnFe）Si type constituents reduces. Al-Mg-Si-Cu aluminium alloys with excessive Si for automotive body sheets can present obviously the paint bake hardenability during the paint bake cycle （i.e. artificial aging at 170 ℃ for 30 min immediately after the solution treatment and quenching）. Suitable Mg content should be controlled in the range of 0.8% and 1.2%（mass fraction）.

关键词：铝镁硅铜合金自动机体板硅化镁冲压成型热处理

Study of vehicle accident reconstruction based on the information of the tire marks

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Journal of Harbin Institute of Technology(New Series) 2007年第5期14卷 641-645页

作者：张晓云金先龙申杰郭磊陈忆九陈建国 school of mechanical engineering Shanghai Jiaotong University Institute of Forensic Science Ministry of Justice

The tire mark is the important legacy information left at the accident scene. Based on the vehicle collision dynamics model, this study provided an optimized algorithm with vehicle final location and other related information for the tire marks. When the tire marks simulation results fit the real one well, the state of vehicle can be understood as the real state in the accident. Based on above, the vehicle velocity and direction are decided. According to the velocity and direction of the vehicle, the complete accident process can be simulated. With the help of the Pc-Crash software, the method has been applied in typical collision accident cases analysis. The reconstruction results will provide the scientific and numerical references for vehicle collision accidents analyzing and appraising.

关键词： vehicle traffic accident reconstruction tire marks

Global Control Simulation of Electric Vehicle Based on Finite State Machine Theory

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Journal of Beijing Institute of Technology 2004年第S1期13卷 68-72页

作者：邹渊孙逢春何洪文 school of mechanical and Vehicular engineering Beijing Institute of Technology Beijing100081China

Finite state machine theory (FSM) is introduced and applied to global control of electric vehicle. Theoretical adaptation for application of FSM in control of electric vehicle is analyzed. Global control logic for parts of electric vehicle is analyzed and built based on FSM. Using Matlab/Simulink, BJD6100-HEV global control algorithm is modeled and prove validity by simulation.

关键词： electric vehicle: finite state machine control algorithm

Modeling, analysis, and optimization of dimensional accuracy of FDM-fabricated parts using definitive screening design and deep learning feedforward artificial neural network

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Advances in Manufacturing 2021年第1期9卷 115-129页

作者： Omar Ahmed Mohamed Syed Hasan Masood Jahar Lal Bhowmik school of engineering Deakin UniversityGeelongAustralia Department of mechanical engineering Higher Institute of Engineering TechnologyBani WalidLibya Department of mechanical and Product Design engineering Swinburne University of TechnologyHawthornVIC 3122Australia Department of Health Science and Biostatistics Swinburne University of TechnologyHawthornVIC 3122Australia

Additive manufacturing(AM)technologies such as fused deposition modeling(FDM)rely on the quality of manufactured products and the process ***,the dimensional accuracy and stability of any AM process is essential for ensuring that customer specifications are satisfied at the highest standard,and variations are controlled without significantly affecting the functioning of processes,machines,and product *** study aims to investigate the effects of FDM fabrication conditions on the dimensional accuracy of cylindrical *** this study,a new class of experimental design techniques for integrated second-order definitive screening design(DSD)and an artificial neural network(ANN)are proposed for designing experiments to evaluate and predict the effects of six important operating *** determining the optimum fabrication conditions to obtain better dimensional accuracies for cylindrical parts,the time consumption and number of complex experiments are reduced considerably in this *** optimum fabrication conditions generated through a second-order DSD are verified with experimental *** results indicate that the slice thickness,part print direction,and number of perimeters significantly affect the percentage of length difference,whereas the percentage of diameter difference is significantly affected by the raster-to-raster air gap,bead width,number of perimeters,and part print ***,the results demonstrate that a second-order DSD integrated with an ANN is a more attractive and promising methodology for AM applications.

关键词： Artificial neural network(ANN) OptimizationDefinitive screening design(DSD) Analysis of variance(ANOVA) Fused deposition modeling(FDM) Dimensional accuracy

Shift scheduling strategy development for parallel hybrid construction vehicles

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Journal of Central South University 2019年第3期26卷 587-603页

作者： LI Tian-yu LIU Hui-ying ZHANG Zhi-wen DING Dao-lin school of mechanical and Aerospace engineering Jilin University school of Electronics and Information engineering Changchun University school of mechanical and Power engineering North University of China

The shift scheduling system of the transmission has an important effect on the dynamic and economic performance of hybrid vehicles. In this work, shift scheduling strategies are developed for parallel hybrid construction vehicles. The effect of power distribution and direction on shift characteristics of the parallel hybrid vehicle with operating loads is evaluated, which must be considered for optimal shift control. A power distribution factor is defined to accurately describe the power distribution and direction in various parallel hybrid systems. This paper proposes a Levenberg-Marquardt algorithm optimized neural network shift scheduling strategy. The methodology contains two objective functions, it is a dynamic combination of a dynamic shift schedule for optimal vehicle acceleration, and an energy-efficient shift schedule for optimal powertrain efficiency. The study is performed on a test bench under typical operating conditions of a wheel loader. The experimental results show that the proposed strategies offer effective and competitive shift performance.

关键词： construction vehicle hybrid electric vehicle shift scheduling strategy shift control neural network

Effects of Heterogeneous Condensation on the Transonic Flow Fields on a Bump Model

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Journal of Thermal Science 2005年第1期14卷 34-40页

作者： Masanori TANAKA Shigeru MATSUO Toshiaki SETOGUCHI Heuy-Dong KIM Department of mechanical engineering Saga University 1 Honjo-machiSaga shiSaga 840-8502JapanDepartment of Mechanical Engineering Saga University1 Honjo-machiSaga shiSaga 840-8502JapanDepartment of Mechanical Engineering Saga University1 Honjo-machiSaga shiSaga 840-8502JapanSchool of Mechanical Engineering College of Natural ScienceAndong National University388Song Cheon DongAndongKyung PookKorea

In the present study, effect of the heterogeneous condensation on the characteristics of shock wave generated on the bump model in the transonic flow field was investigated numerically. As a result, it was found that, for the flow field with steady adiabatic shock wave on the bump model, the condensation with heterogeneous nucleation has a strong effect on the whole flow field, and it reduced the strength of the shock. Furthermore, the total pressure loss was dependent on the concentration of the solid particles per unit volume.

关键词： compressible flow transonic flow heterogeneous condensation simulation.

NUMERICAL SIMULATION OF TURBULENT JETS WITH LATERAL INJECTION INTO A CROSSFLOW

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Journal of Hydrodynamics 2006年第3期18卷 319-323页

作者： GUO Ting-ting LI Shao-hua XU Zhong Department of＇Energy and mechanical engineering Northeast Dianli University Jilin 132012 China school of Energy and Power engineering Xi＇an Jiaotong UniversityXi＇an 710049China

In this paper, Numerical simulations of mean velocity and turbulent kinetic energy fields are presented for three-dimensional lateral jet in crossflow, at the injection angles of -60° and -30 °. The RNG κ- ε turbulence model, with the two-layer wall function method, is adopted to simulate the characteristics of this flow at the jet-to-crossflow velocity ratios, 1, 2 and 4. The results show that the injection angle and jet-to-crossflow velocity ratio can change the flow fields, and the range upstream affected by jet injected laterally increase and the curvature of jet trajectories varies along the flow direction. Furthermore, the separation events in the lee of the jet exit and behind the jet bending-segment have been found, and the mechanisms of two vortex systems are analyzed.

关键词： turbulent jet turbulence model numerical simulation flow field

Run by Run Control of Time-pressure Dispensing for Electronics Encapsulation

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International Journal of Automation and computing 2008年第4期5卷 419-424页

作者： Cong-Ping Chen Han Ding College of mechanical&Materials engineering China Three Gorge UniversityYichang 443002PRC school of mechanical Science and engineering Huazhong University of Science and TechnologyWuhan 430074PRC

To alleviate the influence of gas compressibility on the process performance of time-pressure dispensing for electronics encapsulation,a predictive model is developed based on power-law fluid to estimate the encapsulant amount *** on the simple and effective model,a run by run (RbR) supervisory control scheme is delivered to compensate the variation resulting from gas volume change in the *** simulation and experiment have shown that the dispensing consistency has been greatly improved with the model-based RbR control strategy developed in this paper.

关键词： Time-pressure dispensing predictive model run by run (RbR) control electronics encapsulation.