Pub Date : 2024-06-05DOI: 10.1007/s40534-024-00330-y
Qiliang Li, Yuqing Sun, Menghan Ouyang, Zhigang Yang
Segregated incompressible large eddy simulation and acoustic perturbation equations were used to obtain the flow field and sound field of 1:25 scale trains with three, six and eight coaches in a long tunnel, and the aerodynamic results were verified by wind tunnel test with the same scale two-coach train model. Time-averaged drag coefficients of the head coach of three trains are similar, but at the tail coach of the multi-group trains it is much larger than that of the three-coach train. The eight-coach train presents the largest increment from the head coach to the tail coach in the standard deviation (STD) of aerodynamic force coefficients: 0.0110 for drag coefficient (Cd), 0.0198 for lift coefficient (Cl) and 0.0371 for side coefficient (Cs). Total sound pressure level at the bottom of multi-group trains presents a significant streamwise increase, which is different from the three-coach train. Tunnel walls affect the acoustic distribution at the bottom, only after the coach number reaches a certain value, and the streamwise increase in the sound pressure fluctuation of multi-group trains is strengthened by coach number. Fourier transform of the turbulent and sound pressures presents that coach number has little influence on the peak frequencies, but increases the sound pressure level values at the tail bogie cavities. Furthermore, different from the turbulent pressure, the first two sound pressure proper orthogonal decomposition (POD) modes in the bogie cavities contain 90% of the total energy, and the spatial distributions indicate that the acoustic distributions in the head and tail bogies are not related to coach number.
{"title":"Flow and sound fields of scaled high-speed trains with different coach numbers running in long tunnel","authors":"Qiliang Li, Yuqing Sun, Menghan Ouyang, Zhigang Yang","doi":"10.1007/s40534-024-00330-y","DOIUrl":"https://doi.org/10.1007/s40534-024-00330-y","url":null,"abstract":"<p>Segregated incompressible large eddy simulation and acoustic perturbation equations were used to obtain the flow field and sound field of 1:25 scale trains with three, six and eight coaches in a long tunnel, and the aerodynamic results were verified by wind tunnel test with the same scale two-coach train model. Time-averaged drag coefficients of the head coach of three trains are similar, but at the tail coach of the multi-group trains it is much larger than that of the three-coach train. The eight-coach train presents the largest increment from the head coach to the tail coach in the standard deviation (STD) of aerodynamic force coefficients: 0.0110 for drag coefficient (<i>C</i><sub>d</sub>), 0.0198 for lift coefficient (<i>C</i><sub>l</sub>) and 0.0371 for side coefficient (<i>C</i><sub>s</sub>). Total sound pressure level at the bottom of multi-group trains presents a significant streamwise increase, which is different from the three-coach train. Tunnel walls affect the acoustic distribution at the bottom, only after the coach number reaches a certain value, and the streamwise increase in the sound pressure fluctuation of multi-group trains is strengthened by coach number. Fourier transform of the turbulent and sound pressures presents that coach number has little influence on the peak frequencies, but increases the sound pressure level values at the tail bogie cavities. Furthermore, different from the turbulent pressure, the first two sound pressure proper orthogonal decomposition (POD) modes in the bogie cavities contain 90% of the total energy, and the spatial distributions indicate that the acoustic distributions in the head and tail bogies are not related to coach number.</p>","PeriodicalId":41270,"journal":{"name":"Railway Engineering Science","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141259477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-25DOI: 10.1007/s40534-024-00337-5
Yihao Chi, Hong Xiao, Yang Wang, Zhihai Zhang, Mahantesh M. Nadakatti
Laying the under-sleeper pad (USP) is one of the effective measures commonly used to delay ballast degradation and reduce maintenance workload. To explore the impact of application of the USP on the dynamic and static mechanical behavior of the ballast track in the heavy-haul railway system, numerical simulation models of the ballast bed with USP and without USP are presented in this paper by using the discrete element method (DEM)—multi-flexible body dynamic (MFBD) coupling analysis method. The ballast bed support stiffness test and dynamic displacement tests were carried out on the actual operation of a heavy-haul railway line to verify the validity of the models. The results show that using the USP results in a 43.01% reduction in the ballast bed support stiffness and achieves a more uniform distribution of track loads on the sleepers. It effectively reduces the load borne by the sleeper directly under the wheel load, with a 7.89% reduction in the pressure on the sleeper. Furthermore, the laying of the USP changes the lateral resistance sharing ratio of the ballast bed, significantly reducing the stress level of the ballast bed under train loads, with an average stress reduction of 42.19 kPa. It also reduces the plastic displacement of ballast particles and lowers the peak value of rotational angular velocity by about 50% to 70%, which is conducive to slowing down ballast bed settlement deformation and reducing maintenance costs. In summary, laying the USP has a potential value in enhancing the stability and extending the lifespan of the ballast bed in heavy-haul railway systems.
{"title":"Experimental study and numerical simulation of the impact of under-sleeper pads on the dynamic and static mechanical behavior of heavy-haul railway ballast track","authors":"Yihao Chi, Hong Xiao, Yang Wang, Zhihai Zhang, Mahantesh M. Nadakatti","doi":"10.1007/s40534-024-00337-5","DOIUrl":"https://doi.org/10.1007/s40534-024-00337-5","url":null,"abstract":"<p>Laying the under-sleeper pad (USP) is one of the effective measures commonly used to delay ballast degradation and reduce maintenance workload. To explore the impact of application of the USP on the dynamic and static mechanical behavior of the ballast track in the heavy-haul railway system, numerical simulation models of the ballast bed with USP and without USP are presented in this paper by using the discrete element method (DEM)—multi-flexible body dynamic (MFBD) coupling analysis method. The ballast bed support stiffness test and dynamic displacement tests were carried out on the actual operation of a heavy-haul railway line to verify the validity of the models. The results show that using the USP results in a 43.01% reduction in the ballast bed support stiffness and achieves a more uniform distribution of track loads on the sleepers. It effectively reduces the load borne by the sleeper directly under the wheel load, with a 7.89% reduction in the pressure on the sleeper. Furthermore, the laying of the USP changes the lateral resistance sharing ratio of the ballast bed, significantly reducing the stress level of the ballast bed under train loads, with an average stress reduction of 42.19 kPa. It also reduces the plastic displacement of ballast particles and lowers the peak value of rotational angular velocity by about 50% to 70%, which is conducive to slowing down ballast bed settlement deformation and reducing maintenance costs. In summary, laying the USP has a potential value in enhancing the stability and extending the lifespan of the ballast bed in heavy-haul railway systems.</p>","PeriodicalId":41270,"journal":{"name":"Railway Engineering Science","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2024-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141151943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-22DOI: 10.1007/s40534-024-00329-5
O. Nabochenko, M. Sysyn, Norman Krumnow, Szabolcs Fischer
{"title":"Mechanism of cross-level settlements and void accumulation of wide and conventional sleepers in railway ballast","authors":"O. Nabochenko, M. Sysyn, Norman Krumnow, Szabolcs Fischer","doi":"10.1007/s40534-024-00329-5","DOIUrl":"https://doi.org/10.1007/s40534-024-00329-5","url":null,"abstract":"","PeriodicalId":41270,"journal":{"name":"Railway Engineering Science","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140676929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-09DOI: 10.1007/s40534-024-00331-x
Ahmed S. Aredah, Karim Fadhloun, H. Rakha
{"title":"NeTrainSim: a network-level simulator for modeling freight train longitudinal motion and energy consumption","authors":"Ahmed S. Aredah, Karim Fadhloun, H. Rakha","doi":"10.1007/s40534-024-00331-x","DOIUrl":"https://doi.org/10.1007/s40534-024-00331-x","url":null,"abstract":"","PeriodicalId":41270,"journal":{"name":"Railway Engineering Science","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140723004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-09DOI: 10.1007/s40534-024-00334-8
Philipe Augusto de Paula Pacheco, M. Magelli, Matheus Valente Lopes, P. Corrêa, N. Zampieri, N. Bosso, A. A. dos Santos
{"title":"The effectiveness of different wear indicators in quantifying wear on railway wheels of freight wagons","authors":"Philipe Augusto de Paula Pacheco, M. Magelli, Matheus Valente Lopes, P. Corrêa, N. Zampieri, N. Bosso, A. A. dos Santos","doi":"10.1007/s40534-024-00334-8","DOIUrl":"https://doi.org/10.1007/s40534-024-00334-8","url":null,"abstract":"","PeriodicalId":41270,"journal":{"name":"Railway Engineering Science","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140721815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-09DOI: 10.1007/s40534-024-00333-9
David J. Thompson, Dong Zhao, G. Squicciarini
{"title":"Simplified prediction models for acoustic installation effects of train-mounted equipment","authors":"David J. Thompson, Dong Zhao, G. Squicciarini","doi":"10.1007/s40534-024-00333-9","DOIUrl":"https://doi.org/10.1007/s40534-024-00333-9","url":null,"abstract":"","PeriodicalId":41270,"journal":{"name":"Railway Engineering Science","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140725853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-17DOI: 10.1007/s40534-024-00332-w
Pan Zhang, Shaoguang Li, R. Dollevoet, Zili Li
{"title":"Parametric investigation of railway fastenings into the formation and mitigation of short pitch corrugation","authors":"Pan Zhang, Shaoguang Li, R. Dollevoet, Zili Li","doi":"10.1007/s40534-024-00332-w","DOIUrl":"https://doi.org/10.1007/s40534-024-00332-w","url":null,"abstract":"","PeriodicalId":41270,"journal":{"name":"Railway Engineering Science","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2024-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140234944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-28DOI: 10.1007/s40534-023-00321-5
G. Ferreira, P. Montenegro, José Rui Pinto, António Abel Henriques, R. Calçada
{"title":"A discussion about the limitations of the Eurocode’s high-speed load model for railway bridges","authors":"G. Ferreira, P. Montenegro, José Rui Pinto, António Abel Henriques, R. Calçada","doi":"10.1007/s40534-023-00321-5","DOIUrl":"https://doi.org/10.1007/s40534-023-00321-5","url":null,"abstract":"","PeriodicalId":41270,"journal":{"name":"Railway Engineering Science","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140423155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-19DOI: 10.1007/s40534-023-00328-y
Yuchen Liu, Xiaoqin Lyu, Mingyuan Chang, Qiqi Yang
The low-frequency oscillation (LFO) has occurred in the train–network system due to the introduction of the power electronics of the trains. The modeling and analyzing method in current researches based on electrified railway unilateral power supply system are not suitable for the LFO analysis in a bilateral power supply system, where the trains are supplied by two traction substations. In this work, based on the single-input and single-output impedance model of China CRH5 trains, the node admittance matrices of the train–network system both in unilateral and bilateral power supply modes are established, including three-phase power grid, traction transformers and traction network. Then the modal analysis is used to study the oscillation modes and propagation characteristics of the unilateral and bilateral power supply systems. Moreover, the influence of the equivalent inductance of the power grid, the length of the transmission line, and the length of the traction network are analyzed on the critical oscillation mode of the bilateral power supply system. Finally, the theoretical analysis results are verified by the time-domain simulation model in MATLAB/Simulink.
{"title":"Low-frequency oscillation of train–network system considering traction power supply mode","authors":"Yuchen Liu, Xiaoqin Lyu, Mingyuan Chang, Qiqi Yang","doi":"10.1007/s40534-023-00328-y","DOIUrl":"https://doi.org/10.1007/s40534-023-00328-y","url":null,"abstract":"<p>The low-frequency oscillation (LFO) has occurred in the train–network system due to the introduction of the power electronics of the trains. The modeling and analyzing method in current researches based on electrified railway unilateral power supply system are not suitable for the LFO analysis in a bilateral power supply system, where the trains are supplied by two traction substations. In this work, based on the single-input and single-output impedance model of China CRH5 trains, the node admittance matrices of the train–network system both in unilateral and bilateral power supply modes are established, including three-phase power grid, traction transformers and traction network. Then the modal analysis is used to study the oscillation modes and propagation characteristics of the unilateral and bilateral power supply systems. Moreover, the influence of the equivalent inductance of the power grid, the length of the transmission line, and the length of the traction network are analyzed on the critical oscillation mode of the bilateral power supply system. Finally, the theoretical analysis results are verified by the time-domain simulation model in MATLAB/Simulink.</p>","PeriodicalId":41270,"journal":{"name":"Railway Engineering Science","volume":null,"pages":null},"PeriodicalIF":6.3,"publicationDate":"2024-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139911161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}