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Multi-Objective Optimization of Aluminum Alloy Electric Bus Frame Connectors for Enhanced Durability

Computer Modeling in Engineering & Sciences 2024年第7期140卷 735-755页

作者： Wenjun Zhou mingzhi yang Qian Peng Yong Peng Kui Wang Qiang Xiao Key Laboratory of Traffic Safety on Track Ministry of EducationSchool of Traffic&Transportation EngineeringCentral South UniversityChangsha410018China School of Mechanical and Automotive Engineering Xiamen University of TechnologyXiamen361024China

The widespread adoption of aluminumalloy electric buses,known for their energy efficiency and eco-friendliness,faces a challenge due to the aluminum frame’s susceptibility to deformation compared to steel.This issue is further exacerbated by the stringent requirements imposed by the flammability and explosiveness of batteries,necessitating robust frame protection.Our study aims to optimize the connectors of aluminum alloy bus frames,emphasizing durability,energy efficiency,and safety.This research delves into Multi-Objective Coordinated Optimization(MCO)techniques for lightweight design in aluminum alloy bus body connectors.Our goal is to enhance lightweighting,reinforce energy absorption,and improve deformation resistance in connector components.Three typical aluminum alloy connectors were selected and a design optimization platform was built for their MCO using a variety of software and methods.Firstly,through three-point bending experiments and finite element analysis on three types of connector components,we identified optimized design parameters based on deformation patterns.Then,employing Optimal Latin hypercube design(OLHD),parametric modeling,and neural network approximation,we developed high-precision approximate models for the design parameters of each connector component,targeting energy absorption,mass,and logarithmic strain.Lastly,utilizing the Archive-based Micro Genetic Algorithm(AMGA),Multi-Objective Particle Swarm Optimization(MOPSO),and Non-dominated SortingGenetic Algorithm(NSGA2),we explored optimized design solutions for these joint components.Subsequently,we simulated joint assembly buckling during bus rollover crash scenarios to verify and analyze the optimized solutions in three-point bending simulations.Each joint component showcased a remarkable 30%–40%mass reduction while boosting energy absorption.Our design optimization method exhibits high efficiency and costeffectiveness.Leveraging contemporary automation technology,the design optimization platform developed in this study is poised

关键词： Aluminum connectors three-point bending simulation parametric design model multi-objective collaborative optimization

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Efficient and stable PtFe alloy catalyst for electrocatalytic methanol oxidation with high resistance to CO

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Journal of Energy Chemistry 2024年第3期90卷 327-336,I0008页

作者： Qian yang Sifan Zhang Fengshun Wu Lihua Zhu Guang Li mingzhi Chen An Pei Yingliang Feng Jiangxi Provincial Key Laboratory of Functional Molecular Materials Chemistry College of Chemistry and Chemical EngineeringFaculty of Materials Metallurgy and ChemistryJiangxi University of Science and TechnologyGanzhou 341000JiangxiChina College of Chemistry and Chemical Engineering Xiamen UniversityXiamen 361005FujianChina

Direct methanol fuel cells(DMFC) are widely considered to be an ideal green energy conversion device but their widespread applications are limited by the high price of the Pt-based catalysts and the instability in terms of surface CO toxicity in long-term operation.Herein,the PtFe alloy nanoparticles(NPs) with small particle size(~4.12 nm) supported on carbon black catalysts with different Pt/Fe atomic ratios(Pt_(1)Fe_(2)/C,Pt_(3)Fe_(4)/C,Pt_(1)Fe_(1)/C,and Pt_(2)Fe_(1)/C) are successfully prepared for enhanced anti-CO poisoning during methanol oxidation reaction(MOR).The optimal atomic ratio of Pt/Fe for the MOR is 1:2,and the mass activity of Pt_(1)Fe_(2)/C(5.40 A mg_(Pt)^(-1)) is 13.5 times higher than that of conventional commercial Pt/C(Pt/C-JM)(0.40 A mg_(Pt)^(-1)).The introduction of Fe into the Pt lattice forms the PtFe alloy phase,and the electron density of Pt is reduced after forming the PtFe alloy.In-situ Fourier transform infrared results indicate that the addition of oxyphilic metal Fe has reduced the adsorption of reactant molecules on Pt during the MOR.The doping of Fe atoms helps to desorb toxic intermediates and regenerate Pt active sites,promoting the cleavage of C-O bonds with good selectivity of CO_(2)(58.1%).Moreover,the Pt_(1)Fe_(2)/C catalyst exhibits higher CO tolerance,methanol electrooxidation activity,and long-term stability than other Pt_(x)Fe_(y)/C catalysts.

关键词： Alloy catalyst PtFe Methanol oxidation In-situ FTIR CO resistance

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Kinetic model of vibration screening for granular materials based on biological neural network

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Particuology 2024年第5期88卷 98-106页

作者： Zhan Zhao Yan Zhang Fang Qin mingzhi Jin School of Agricultural Engineering Jiangsu UniversityZhenjiang212013China Shandong Academy of Agricultural Machinery Sciences Ji'nan250100China

The kinetic model is the theoretical basis for optimizing the structure and operation performance of vibration screening devices.In this paper,a biological neurodynamic equation and neural connections were established according to the motion and interaction properties of the material under vibration excitation.The material feeding to the screen and the material passing through apertures were considered as excitatory and inhibitory inputs,respectively,and the generated stable neural activity landscape was used to describe the material distribution on the 2D screen surface.The dynamic process of material vibration screening was simulated using discrete element method(DEM).By comparing the similarity between the material distribution established using biological neural network(BNN)and that obtained using DEM simulation,the optimum coefficients of BNN model under a certain screening parameter were determined,that is,one relationship between the BNN model coefficients and the screening operation parameters was established.Different screening parameters were randomly selected,and the corresponding relationships were established as a database.Then,with straw/grain ratio,aperture diameter,inclination angle,vibration strength in normal and tangential directions as inputs,five independent adaptive neuro-fuzzy inference systems(ANFIS)were established to predict the optimum BNN model coefficients,respectively.The training results indicated that ANFIS models had good stability and accuracy.The flexibility and adaptability of the proposed BNN method was demonstrated by modeling material distribution under complex feeding conditions such as multiple regions and non-uniform rate.

关键词： Kinetic model Material distribution Vibration screening Biological neural network DEM simulation Adaptive neuro-fuzzy inference systems

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Advances in ground heat exchangers for space heating and cooling:Review and perspectives

Energy and Built Environment

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Energy and Built Environment 2024年第2期5卷 255-269页

作者： Ping Cui Weibo yang Wenke Zhang Ke Zhu Jeffrey D.Spitler mingzhi Yu School of Thermal Engineering Shandong Jianzhu UniversityJinanShandong 250101China College of Electrical Energy and Power EngineeringYangzhou UniversityYangzhouJiangsu 225127China Department of Mechanical Engineering Oklahoma State UniversityStillwaterOKUSA

As a renewable energy source,geothermal energy has been widely used to provide space heating and cooling for buildings.The thermal performance of ground heat exchanger(GHE)is significant for the operating efficiency of the ground source heat pump(GSHP)systems.This paper presents a comprehensive review of developments and advances of three kinds of GHE,including vertical borehole GHE(VBGHE),Pile GHE(PGHE),and deep borehole GHE(DBGHE)which are currently popular in larger GSHP systems.Firstly,analytical models proposed to ana-lyze heat transfer process of VBGHE with different geological conditions are summarized,such as homogenous or heterogeneous ground,with or without groundwater advection.Numerical and short-time step models and measures to improve GHE thermal performance are also reviewed.Secondly,a summary of research advances in PGHE is provided,which includes the heat transfer models of PGHE,the effects of geometric structure,oper-ation modes,pile spacing,use of phase change material(PCM),thermal properties of PCM,thermo-mechanical behavior and/or thermal performance of PGHE.The effects of groundwater flow direction and velocity on PGHE are also summarized in brief.Lastly,models of three kinds of DBGHEs,i.e.,deep coaxial GHE(DCGHE),deep U-bend GHE(DUGHE)and super-long gravity heat pipe(SLGHP),are reviewed.The physical bases of the dif-ferent analytical models are elaborated and also their advantages and disadvantages are described.Advances in numerical modelling and improving numerical model calculation speed of DCBHE,DCBHE array,and DUBHE are summarized.The review provides a meaningful reference for the further study of GHEs.

关键词： Vertical borehole ground heat exchanger Pile ground heat exchanger Deep borehole ground heat exchanger Modelling

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Numerical study of the influence of dome shape on the unsteady aerodynamic performance of a high-speed train's pantograph subjected to crosswind

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Journal of Traffic and Transportation Engineering(English Edition) 2023年第1期10卷 13-30页

作者： Xiaofang Li Dan Zhou Lirong Jia mingzhi yang Key Laboratory of Traffic Safety on Track of Ministry of Education School of Traffic and Transportation EngineeringCentral South UniversityChangsha 410075China Joint International Research Laboratory of Key Technology for Rail Traffic Safety Central South UniversityChangsha 410075China National&Local Joint Engineering Research Center of Safety Technology for Rail Vehicle Central South UniversityChangsha 410075China CSR Qingdao Sifang Co.Ltd. Qingdao 266111China

This study aims to investigate the unsteady aerodynamic performance of a high-speed train’s pantograph with respect to two different dome shapes and without dome under a20°yaw angle using a delayed detached eddy simulation method.Further,the influence of the dome shape on the simulation results is determined.The accuracy of the numerical method was validated by comparing a few of the numerical results with the wind tunnel test results,and high consistency was observed.An analysis of aerodynamic forces and flow structures around the pantograph was performed.The dome had significant influence on velocity field distribution surrounding the pantograph,particularly in the wake of flow region.Compared with the case where the dome was absent,vortex intensity around the pantograph increased after installing the dome.The existence of the bathtub-type dome resulted in greater flow field disturbance and vortex strength than the baffle-type dome.Moreover,the dome considerably affected time-averaged aerodynamic coefficients and their fluctuations,especially the bathtub-type dome.Additionally,the power spectral density of the unsteady aerodynamic coefficient of each pantograph component exhibited significant peaks and typical broadband distribution characteristics.

关键词： High-speed train Crosswind Pantograph Dome Unsteady aerodynamic performance

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High‑Entropy Layered Oxide Cathode Enabling High‑Rate for Solid‑State Sodium‑Ion Batteries

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Nano-Micro Letters 2024年第1期16卷 160-171页

作者： Tianxun Cai mingzhi Cai Jinxiao Mu Siwei Zhao Hui Bi Wei Zhao Wujie Dong Fuqiang Huang State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050People’s Republic of China State Key Laboratory of Rare Earth Materials Chemistry and Applications College of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871People’s Republic of China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049People’s Republic of China Zhongke Institute of Strategic Emerging Materials Yixing 214213JiangsuPeople’s Republic of China

Na-ion O3-type layered oxides are prospective cathodes for Na-ion batteries due to high energy density and low-cost.Nevertheless,such cathodes usually suffer from phase transitions,sluggish kinetics and air instability,making it difficult to achieve high performance solid-state sodium-ion batteries.Herein,the high-entropy design and Li doping strategy alleviate lattice stress and enhance ionic conductivity,achieving high-rate performance,air stability and electrochemically thermal stability for Na_(0.95)Li_(0.06)Ni_(0.25)Cu_(0.05)Fe_(0.15)Mn_(0.49)O_(2).This cathode delivers a high reversible capacity(141 mAh g^(−1)at 0.2C),excellent rate capability(111 mAh g^(−1)at 8C,85 mAh g^(−1)even at 20C),and long-term stability(over 85%capacity retention after 1000 cycles),which is attributed to a rapid and reversible O3–P3 phase transition in regions of low voltage and suppresses phase transition.Moreover,the compound remains unchanged over seven days and keeps thermal stability until 279℃.Remarkably,the polymer solid-state sodium battery assembled by this cathode provides a capacity of 92 mAh g^(−1)at 5C and keeps retention of 96%after 400 cycles.This strategy inspires more rational designs and could be applied to a series of O3 cathodes to improve the performance of solid-state Na-ion batteries.

关键词： High-entropy High-rate performance Li-TM interaction Air stability O3 layered oxide cathode

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Development of a deviation package method for low-cost robust optimization in compressor blade design

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Chinese Journal of Aeronautics 2024年第4期37卷 166-180页

作者： mingzhi LI Xianjun YU Dejun MENG Guangfeng AN Baojie LIU Research Institute of Aero-Engine Beihang UniversityBeijing 100191China National Key Laboratory of Science&Technology on Aero-Engine Aero-Thermodynamics Beihang UniversityBeijing 100191China AECC Shenyang Engine Research Institute Shenyang 110015China

Manufacture variations can greatly increase the performance variability of compressor blades. Current robust design optimization methods have a critical role in reducing the adverse impact of the variations, but can be affected by errors if the assumptions of the deviation models and distribution parameters are inaccurate. A new approach for robust design optimization without the employment of the deviation models is proposed. The deviation package method and the interval estimation method are exploited in this new approach. Simultaneously, a stratified strategy is used to reduce the computational cost and assure the optimization accuracy. The test case employed for this study is a typical transonic compressor blade profile, which resembles most of the manufacture features of modern compressor blades. A set of 96 newly manufactured blades was measured using a coordinate measurement machine to obtain the manufacture variations and produce a deviation package. The optimization results show that the scatter of the aerodynamic performance for the optimal robust design is 20% less than the baseline value. By comparing the optimization results obtained from the deviation package method with those obtained from widely-used methods employing the deviation model, the efficiency and accuracy of the deviation package method are demonstrated. Finally, the physical mechanisms that control the robustness of different designs were further investigated, and some statistical laws of robust design were extracted.

关键词： Manufacture variations Robust design optimization Compressor leading edge Aerodynamics Physical mechanism

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Promoted catalytic performance of Ag-Mn bimetal catalysts synthesized through reduction route

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Journal of Environmental Sciences 2024年第3期137卷 358-369页

作者： Wenkai Hu Tao Guo Kaiyao Ma Xu Li Wangting Luo mingzhi Wu Hao Guo Yaxin Zhang Wenfeng Shangguan School of Chemical Engineering and Technology Xinjiang UniversityUrumchi 830017China Research Center for Combustion and Environmental Technology Shanghai Jiao Tong UniversityShanghai 200240China

VOCs can exert great harm to both human and environment,and catalytic oxidation is believed to be an effective technique to eliminate these pollutants.In this paper,Ag-Mn bimetal catalysts with 10 wt.%of silver were synthesized using doping,impregnation,and reduction methods respectively,and then they were applied to the catalytic oxidation of benzene.Through series of characterizations it showed that the loading of silver using reduction method significantly resulted in improved physico-chemical properties of manganese oxides,such as larger surface area and pore volume,higher proportion of surface Mn~(3+)and Mn~(4+),stronger reducibility and more active of surface oxygen species,which were all beneficial to its catalytic activity.As a result,the Ag-Mn catalysts synthesized by reduction method showed a lower T_(90)value(equals to the temperature at which 90%of initial benzene was removed)of 203℃.Besides,both the used and fresh Ag-Mn catalysts synthesized by reduction method showed preferable stability in this research.

关键词： Ag-Mn Benzene oxidation Catalytic performance Reduction route

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Research on numerical simulation of transient pressure for high-speed train passing through the most unfavourable length tunnel

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Transportation Safety and Environment 2023年第3期5卷 78-91页

作者： Zhao Liu Feng Liu Shuanbao Yao Dawei Chen mingzhi yang College of Mechanical Engineering Taiyuan University of TechnologyTaiyuan 030024China CRRC Qingdao Sifang Co.Ltd Qingdao 266111China Key Laboratory of Traffic Safety on Track of Ministry of Education Central South UniversityChangsha 410075China

The length of high-speed railway tunnel is an important factor affecting transient pressure of high-speed train.When the tunnel length is the most unfavourable,the transient pressure changes in the tunnel and on the surface of the train are the most severe,which may affect the safe operation of the train or damage the structure in the tunnel.Based on the three-dimensional,compressible,unsteady N-S equation and finite volume method,this paper uses the CFD numerical simulation method to study the change and amplitude distribution of the transient pressure on the train surface and the tunnel when a high-speed train passes through the most unfavourable length tunnel.A fast calculation method is proposed to save the cost of calculation;it has great applicability of pressure amplitude.The results show that the pressure distribution in the tunnel and on the surface of the train is affected by the train speed,the length of the train and the position of the measuring point.The minimum negative peak value in the tunnel appears at the position where the superposition phenomenon is the most severe,and the position will change with the speed of the train.There are two negative peak waveforms of the train surface pressure,and the first waveformn is greatly affected by the train speed.It improves a reference for studying the strength requirement of the most unfavourable length tunnels and trains,and ensures the safe operation of trains in tunnels of different lengths.

关键词： transient pressure high-speed train most unfavourable tunnel length

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转向架腹板结构对高速列车气动噪声的影响

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铁道科学与工程学报 2024年第3期21卷 924-935页

作者：袁野杨明智中南大学轨道交通安全教育部重点实验室湖南长沙410075 轨道交通安全关键技术国际合作联合实验室湖南长沙410075 轨道交通列车安全保障技术国家地方联合工程研究中心湖南长沙410075

随着列车运行速度的不断提高,气动噪声问题日益突出,需要有效控制高速列车的气动噪声。为降低高速列车转向架区域的气动噪声,基于IDDES模型与FW-H声学方程,建立转向架不安装腹板及安装腹板的1:8缩比模型,通过数值仿真探究400 km时速下,... 详细信息

随着列车运行速度的不断提高,气动噪声问题日益突出,需要有效控制高速列车的气动噪声。为降低高速列车转向架区域的气动噪声,基于IDDES模型与FW-H声学方程,建立转向架不安装腹板及安装腹板的1:8缩比模型,通过数值仿真探究400 km时速下,转向架区域安装腹板后流场特性、噪声源强度、远场辐射噪声频谱特性和声压级幅值的变化,分析腹板对整车及转向架区域气动噪声的影响。研究结果表明:转向架区域底部安装腹板后,腹板的导流作用减缓了转向架部位的流体冲击和流体相互作用,抑制了转向架区域涡的形成,各频率下,转向架前、后轮对及构架的脉动压力级明显减小,有效降低了转向架区域气动噪声源的强度;转向架安装腹板后,各测点在200~1 000 Hz以及2 000 Hz以上频段的声压级幅值下降,其远场辐射噪声总声压级幅值也有所降低,其中,整车远场辐射噪声总声压级平均值降低2.33 dB(A),转向架辐射噪声总声压级平均值降低4.03 dB(A),转向架辐射噪声能量占整车辐射噪声能量的比例从53.2%下降到27.8%,转向架区域气动噪声得到有效控制;头车一位端转向架的降噪效果最好,辐射噪声总声压级平均值下降了5.88 dB(A),腹板对转向架辐射噪声的控制主要体现在对前、后轮对及构架等部件辐射噪声的控制。研究结果可为进一步优化高速列车气动噪声提供一定参考。

关键词：气动噪声高速列车转向架腹板流场降噪

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