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Effect of Bogie Cavity End Wall Inclination on Flow Field and Aerodynamic noise in the Bogie Region of High-Speed Trains

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 2175-2195页

作者： Jiawei Shi jiye Zhang State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu610031China

Combining the detached eddy simulation(DES)method and Ffowcs Williams-Hawkings(FW-H)equation,the effect of bogie cavity end wall inclination on the flow field and aerodynamic noise in the bogie region is numerically ***,the simulation is conducted based on a simplified cavity-bogie model,including five cases with different inclination angles of the front and rear walls of the *** comparing and analyzing the flow field and acoustic results of the five cases,the influence of the regularity and mechanism of the bogie cavity end wall inclination on the flow field and the aerodynamic noise of the bogie region are ***,the noise reduction strategy determined by the results of the simplified cavity-bogie model is applied to a three-car marshaling train model to verify its effectiveness when applied to the real *** results reveal that the forward inclination of the cavity front wall enlarges the influence area of shear vortex structures formed at the leading edge of the cavity and intensifies the interaction between the vortex structures and the front wheelset,frontmotor,and front gearbox,resulting in the increase of the aerodynamic noise generated by the bogie *** backward inclination of the cavity rear wall is conducive to guiding the vortex structures flow out of the cavity and weakening the interaction between the shear vortex structures and the cavity rear wall,leading to the reduction of the aerodynamic noise generated by the bogie *** the rear end wall of the foremost bogie cavity of the head car is a feasible aerodynamic noise reduction measure for high-speed trains.

关键词： Bogie cavity flow aerodynamic noise end wall inclination

Effect of streamlined nose length on aerodynamic performance of high-speed train with a speed of 400 km/h

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第7期25卷 525-540页

作者： nianxun LI Tian LI Zhiyuan DAI Deng QIn jiye ZHAnG State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu 610031China

The streamlined nose length(SnL)plays a crucial role in determining the aerodynamic performance of high-speed *** appropriate SnL can not only effectively reduce the magnitude of aerodynamic drag and lift forces,but also improve the performance of the high-speed train in tunnel passing and crosswind *** this study,a numerical simulation of the aerodynamic performance of high-speed trains at a speed of 400 km/h,with varying SnLs,is conducted using the k-ωshear stress transport(SST)turbulence *** different SnLs include 6.0,7.0,8.0,9.0,9.8,12.0,15.0,and 18.0 *** order to validate the accuracy of the numerical simulation,its results are compared with wind tunnel test data obtained from the *** simulation is carried out using compressible and incompressible gases to determine the effect of gas compressibility on *** impact of SnL on the aerodynamic performance of the trains is analyzed in terms of aerodynamic forces,velocity,and pressure *** comparison to the original train,the train with a 6.0 m SnL experienced a 10.8%increase in overall aerodynamic ***,the lift forces on the head and tail cars increased by 35.7%and 75.5%,*** the other hand,the train with an 18.0 m SnL exhibited a 16.5%decrease in aerodynamic ***,the lift forces on the head and tail cars decreased by 21.9%and 49.7%,*** aerodynamic drag force of the entire train varies linearly with the SnL,while the aerodynamic lift of the tail car follows a quadratic function in relation to the SnL.

关键词： Streamlined nose length(SnL) High-speed train Aerodynamic performance numerical simulation Flow structures

numerical Study on Reduction in Aerodynamic Drag and noise of High-Speed Pantograph

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 2155-2173页

作者： Deng Qin Xing Du Tian Li jiye Zhang State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu610031China School of Electrical Engineering Southwest Jiaotong UniversityChengdu610031China

Reducing the aerodynamic drag and noise levels of high-speed pantographs is important for promoting environmentally friendly,energy efficient and rapid advances in train *** computational fluid dynamics theory and the K-FWH acoustic equation,a numerical simulation is conducted to investigate the aerodynamic characteristics of high-speed pantographs.A component optimization method is proposed as a possible solution to the problemof aerodynamic drag and noise in high-speed *** results of the study indicate that the panhead,base and insulator are the main contributors to aerodynamic drag and noise in high-speed ***,a gradual optimization process is implemented to improve the most significant components that cause aerodynamic drag and *** optimizing the cross-sectional shape of the strips and insulators,the drag and noise caused by airflow separation and vortex shedding can be *** aerodynamic drag of insulator with circular cross section and strips with rectangular cross section is the *** insulators and optimizing the chamfer angle and height of the windward surface of the strips can improve the aerodynamic performance of the *** addition,the streamlined fairing attached to the base can eliminate the complex flow and shield the radiated *** contrast to the original pantograph design,the improved pantograph shows a 21.1%reduction in aerodynamic drag and a 1.65 dBA reduction in aerodynamic noise.

关键词： High-speed pantograph aerodynamic drag aerodynamic noise reduction optimizing

Enhanced performance of solution-processed carbon nanotube transparent electrodes in foldable perovskite solar cells through vertical separation of binders by using eco-friendly parylene substrate

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Carbon Energy 2024年第7期6卷 83-93页

作者： Unsoo Kim Jeong-Seok nam Jungjin Yoon jiye Han Mansoo Choi Il Jeon Department of Mechanical Engineering Seoul National UniversitySeoulRepublic of Korea Global Frontier Center for Multiscale Energy Systems Seoul National UniversitySeoulRepublic of Korea Frontier Energy Solution SeoulRepublic of Korea Department of nano Engineering Department of Nano Science and TechnologySKKU Advanced Institute of Nanotechnology(SAINT)Sungkyunkwan University(SKKU)SuwonRepublic of Korea Department of Materials Science and Engineering Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA

The successful utilization of an eco-friendly and biocompatible parylene-C substrate for high-performance solution-processed double-walled carbon nanotube(CnT)electrode-based perovskite solar cells(PSCs)was *** the use of a novel inversion transfer technique,vertical separation of the binders from the CnTs was induced,rendering a stronger p-doping effect and thereby a higher conductivity of the *** resulting foldable devices exhibited a power conversion efficiency of 18.11%,which is the highest reported among CnT transparent electrode-based PSCs to date,and withstood more than 10,000 folding cycles at a radius of 0.5 mm,demonstrating unprecedented mechanical ***,solar modules were fabricated using entirely laser scribing processes to assess the potential of the solution-processable nanocarbon ***,this is the only one to be processed entirely by the laser scribing process and to be biocompatible as well as eco-friendly among the previously reported nonindium tin oxide-based perovskite solar modules.

关键词： double-walled carbon nanotubes parylene substrates perovskite modules perovskite solar cells solution-processable electrodes surfactant removal

numerical Simulations of Snow Accumulation in the Bogie Region of a Train Considering Snow Particle Rotation

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Fluid Dynamics & Materials Processing 2024年第10期20卷 2337-2352页

作者： Hong Lan jiye Zhang Yao Zhang Lu Cai State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu610031China College of Railway Transportation Hunan University of TechnologyZhuzhou412000China GD Midea Air-Conditioning Equipment Co. Ltd.Foshan528311China

To investigate the influence of snow particle rotational motion on the accumulation of snow in the bogie region of high-speed trains,an Euler‒Lagrange numerical approach is *** study examines the effects of snow particle diameter and train speed on the ensuing *** is shown that considering snow particle rotational motion causes significant deviation in the particle trajectories with respect to non-rotating *** a deviation increases with larger snow particle diameters and higher train *** snow accumulation on the overall surface of the bogie increases,and the amount of snow on the vibration reduction device varies *** certain conditions,the amount of accumulated snow can increase by several orders of magnitudes.

关键词： High-speed train bogie snow particle rotation discrete phase model snow accumulation

numerical Study on the Effect of Vortex Generators on the Aerodynamic Drag of a High-Speed Train

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Fluid Dynamics & Materials Processing 2024年第2期20卷 463-473页

作者： Tian Li Hao Liang Zerui Xiang jiye Zhang State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu610031China School of Design Southwest Jiaotong UniversityChengdu610031China

A relatively high aerodynamic drag is an important factor that hinders the further acceleration of high-speed *** the shear stress transport(SST)k-ωturbulence model,the effect of various vortex generator types on the aerodynamic characteristics of an ICE2(Inter-city Electricity)train has been *** results indi-cate that the vortex generators with wider triangle,trapezoid,and micro-ramp arranged on the surface of the tail car can signiﬁcantly change the distribution of surface pressure and affect the vorticity intensity in the *** alteration effectively reduces the resistance of the tail ***,the micro-ramp vortex generator with its convergent structure at the rear exhibits enhancedﬂow-guiding capabilities,resulting in a 15.4%reduction in the drag of the tail car.

关键词： Vortex generator aerodynamic drag reduction numerical simulation

Influence of Anteroposterior Symmetrical Aero-Wings on the Aerodynamic Performance of High-Speed Train

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Computer Modeling in Engineering & Sciences 2024年第4期139卷 937-953页

作者： Peiheng He jiye Zhang Lan Zhang Jiaqi Wang Yuzhe Ma State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu610031China

The running stability of high-speed train is largely constrained by the wheel-rail coupling relationship,and the continuous wear between the wheel and rail surfaces will profoundly affect the dynamic performance of the *** recent years,under the background of increasing train speed,some scientific researchers have proposed a new idea of using the lift force generated by the aerodynamic wings(aero-wing)installed on the roof to reduce the sprung load of the carriage in order to alleviate the wear and tear of the wheel and *** on the bidirectional running characteristics of high-speed train,this paper proposes a scheme to apply aero-wings with anteroposterior symmetrical cross-sections on the roof of the *** the verification of the wind tunnel experimental data,the relatively better airfoil section and extension formof anteroposterior symmetrical aero-wing is selected respectively in this paper,and the aero-wings are fixedly connected to the roof of the train through the mounting column to conduct aerodynamic simulation *** research shows that:compared with the circular-arc and oval crosssections,this paper believes that the crescent cross-section can form greater aerodynamic lift force in a limited *** factors such as aerodynamic parameters,ground effect,and manufacturing process,this paper proposes to adopt aero-wings with arc type extension form and connect them to the roof of the train through mounting columns with shuttle *** the roof of the train is covered with aero-wings and runs at high speed,the sprung load of the carriages can be effectively ***,there are certain hidden dangers in the tail carriage due to the large amount of lift force,so,the intervention of the aero-wing lifting mechanism is *** the same time,it is necessary to optimize the overall aerodynamic drag force reduction in the followup work.

关键词： Anteroposterior symmetrical aero-wing wheel-rail wear aerodynamic lift force ground effect numerical simulation

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社会治理现代化视域下矛盾纠纷多元化解路径

法治现代化研究 2024年第3期8卷 15-28页

作者：周继业周成江苏省法学会江苏省高级人民法院

深入探讨习近平法治思想在推动多元解纷机制建设,实现社会治理现代化过程中的核心作用。要解决当前困扰多元解纷机制发展的现实难题,必须始终坚持以习近平法治思想为指引,充分汲取习近平法治思想中关于社会治理的理论养分,坚持党的领导... 详细信息

深入探讨习近平法治思想在推动多元解纷机制建设,实现社会治理现代化过程中的核心作用。要解决当前困扰多元解纷机制发展的现实难题,必须始终坚持以习近平法治思想为指引,充分汲取习近平法治思想中关于社会治理的理论养分,坚持党的领导、注重民主与法治、抓住基层关键节点、强调德法共治、加强新技术运用。在构建路径上要以完善相关法律法规为引领、以加强党政领导为重点、以强化诉调对接为突破、以推动智能化建设为抓手,从而推动形成人人有责、人人尽责、人人享有的社会治理新格局。

关键词：习近平法治思想多元解纷机制路径探析

时空融合的堆石坝变形预测模型及在安全监测中的应用

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水利学报 2024年第5期55卷 564-576页

作者：吴继业马刚艾志涛杨启贵周伟武汉大学水资源工程与调度全国重点实验室湖北武汉430072 武汉大学水工程科学研究院湖北武汉430072 武汉大学水工岩石力学教育部重点实验室湖北武汉430072 长江设计集团有限公司湖北武汉430010

变形预测是堆石坝安全监测与健康诊断的重要手段,现有研究多根据堆石坝监测数据建立单测点预测模型,未充分考虑测点之间相关性进行整体建模,且现有模型难以对漂移数据进行长期精准预测。本文考虑堆石坝变形序列的时序依赖性和测点之间... 详细信息

变形预测是堆石坝安全监测与健康诊断的重要手段,现有研究多根据堆石坝监测数据建立单测点预测模型,未充分考虑测点之间相关性进行整体建模,且现有模型难以对漂移数据进行长期精准预测。本文考虑堆石坝变形序列的时序依赖性和测点之间的协同相关性,提出了基于图卷积和循环神经网络、引入概率预测与全过程训练的时空融合变形预测模型。该模型首先采用图卷积网络对多测点特征进行自适应汇聚,然后利用循环神经网络中细胞状态与隐层记忆沿时间轴的传递性,实现对时空信息的挖掘与融合,最后通过线性层得到概率预测参数,提高了模型对监测数据噪声的鲁棒性。采用全过程训练方式,提高模型对影响因子与累积变形量内在关系的学习能力,实现对漂移数据的长期精准预测。最后以水布垭面板堆石坝为例,进行了模型对比实验与消融实验,介绍了该模型在堆石坝安全监测和健康诊断中的三种具体应用。结果表明,本文模型有效融合了时空信息,在预测精度方面显著高于现有模型,解决了现有模型对大坝整体变形规律学习能力差、漂移数据预测精度低的问题,可用于堆石坝变形长期预测、测点异常检测与缺损数据补全。

关键词：堆石坝变形预测时空融合图卷积网络长短期记忆网络概率预测