Application of periodic boundaries in freight train aerodynamic performance simulations
The length of long marshalling freight train and the non-streamline shape of wagon lead to more difficulties in simulating the aerodynamic performances. To simplify the simulation process of long freight trains and conserve computational resources, periodic boundary conditions and the improved delay...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2023-05-01
|
| Series: | Alexandria Engineering Journal |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S1110016823001473 |
| _version_ | 1797833153532919808 |
|---|---|
| author | Gaopeng Liang Tanghong Liu Yutao Xia Zhengwei Chen Xiao Dong Xiaodong Chen |
| author_facet | Gaopeng Liang Tanghong Liu Yutao Xia Zhengwei Chen Xiao Dong Xiaodong Chen |
| author_sort | Gaopeng Liang |
| collection | DOAJ |
| description | The length of long marshalling freight train and the non-streamline shape of wagon lead to more difficulties in simulating the aerodynamic performances. To simplify the simulation process of long freight trains and conserve computational resources, periodic boundary conditions and the improved delayed detached eddy simulation based on the shear-stress transport k-ω turbulence model were employed in this study. To better analyze the aerodynamic coefficients of full-scale, nine-boxcar, and periodic-boundary simulations, the pressure and viscous drag were analyzed separately. Aerodynamic coefficients and surrounding flows of freight trains obtained from periodic-boundary, full-scale, and nine-boxcar simulation methods are compared in detail to investigate the feasibility of the periodic-boundary condition for numerical simulations of long freight trains. The dependence of the computational mesh was verified in the STAR-CCM + software. Simulation results show that the deviations of drag coefficient under the periodic-boundary and full-scale conditions is 7.6 %, and that of the nine-boxcar and full-scale conditions is 5.7 %. Based on the simulated flow fields, the variations of pressure and velocity fields around the test wagon are similar in these three simulations. Besides, the distribution of detached vortices around the test wagon are similar in simulations. Moreover, locomotive has no significant influence on aerodynamic performances of the fifth wagon in the simulation of one locomotive with nine boxcars. In this study, the computing time of full-scale condition is 58 hours, and that of periodic-boundary condition is one-tenth of full-scale condition. Consequently, it can be concluded that the periodic boundary is a potential choice in aerodynamic simulations of a long freight train, better balancing the simulation accuracy and efficiency. |
| first_indexed | 2024-04-09T14:19:59Z |
| format | Article |
| id | doaj.art-c7d79eb4fa3a455d9c0b92049f34d083 |
| institution | Directory Open Access Journal |
| issn | 1110-0168 |
| language | English |
| last_indexed | 2024-04-09T14:19:59Z |
| publishDate | 2023-05-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Alexandria Engineering Journal |
| spelling | doaj.art-c7d79eb4fa3a455d9c0b92049f34d0832023-05-05T04:39:58ZengElsevierAlexandria Engineering Journal1110-01682023-05-0170315329Application of periodic boundaries in freight train aerodynamic performance simulationsGaopeng Liang0Tanghong Liu1Yutao Xia2Zhengwei Chen3Xiao Dong4Xiaodong Chen5Key Laboratory of Traffic Safety on Track of Ministry of Education, School of Traffic＆Transportation Engineering, Central south University, Changsha 410075, China; Joint International Research Laboratory of Key Technology for Rail Traffic Safety, Changsha 410075, China; National & Local Joint Engineering Research Centre of Safety Technology for Rail Vehicle, Central South University, Changsha 410075, ChinaKey Laboratory of Traffic Safety on Track of Ministry of Education, School of Traffic＆Transportation Engineering, Central south University, Changsha 410075, China; Joint International Research Laboratory of Key Technology for Rail Traffic Safety, Changsha 410075, China; National & Local Joint Engineering Research Centre of Safety Technology for Rail Vehicle, Central South University, Changsha 410075, China; Corresponding author.Key Laboratory of Traffic Safety on Track of Ministry of Education, School of Traffic＆Transportation Engineering, Central south University, Changsha 410075, China; Joint International Research Laboratory of Key Technology for Rail Traffic Safety, Changsha 410075, China; National & Local Joint Engineering Research Centre of Safety Technology for Rail Vehicle, Central South University, Changsha 410075, ChinaNational Rail Transit Electrification and Automation Engineering Technology Research Center (Hong Kong Branch), Hung Hom, Kowloon, Hong Kong SAR, China; Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR, ChinaKey Laboratory of Traffic Safety on Track of Ministry of Education, School of Traffic＆Transportation Engineering, Central south University, Changsha 410075, China; Joint International Research Laboratory of Key Technology for Rail Traffic Safety, Changsha 410075, China; National & Local Joint Engineering Research Centre of Safety Technology for Rail Vehicle, Central South University, Changsha 410075, ChinaDepartment of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester, M13 9PL, UKThe length of long marshalling freight train and the non-streamline shape of wagon lead to more difficulties in simulating the aerodynamic performances. To simplify the simulation process of long freight trains and conserve computational resources, periodic boundary conditions and the improved delayed detached eddy simulation based on the shear-stress transport k-ω turbulence model were employed in this study. To better analyze the aerodynamic coefficients of full-scale, nine-boxcar, and periodic-boundary simulations, the pressure and viscous drag were analyzed separately. Aerodynamic coefficients and surrounding flows of freight trains obtained from periodic-boundary, full-scale, and nine-boxcar simulation methods are compared in detail to investigate the feasibility of the periodic-boundary condition for numerical simulations of long freight trains. The dependence of the computational mesh was verified in the STAR-CCM + software. Simulation results show that the deviations of drag coefficient under the periodic-boundary and full-scale conditions is 7.6 %, and that of the nine-boxcar and full-scale conditions is 5.7 %. Based on the simulated flow fields, the variations of pressure and velocity fields around the test wagon are similar in these three simulations. Besides, the distribution of detached vortices around the test wagon are similar in simulations. Moreover, locomotive has no significant influence on aerodynamic performances of the fifth wagon in the simulation of one locomotive with nine boxcars. In this study, the computing time of full-scale condition is 58 hours, and that of periodic-boundary condition is one-tenth of full-scale condition. Consequently, it can be concluded that the periodic boundary is a potential choice in aerodynamic simulations of a long freight train, better balancing the simulation accuracy and efficiency.http://www.sciencedirect.com/science/article/pii/S1110016823001473Freight trainOpen trackIDDESPeriodic boundaryFlow fieldAerodynamic resistance |
| spellingShingle | Gaopeng Liang Tanghong Liu Yutao Xia Zhengwei Chen Xiao Dong Xiaodong Chen Application of periodic boundaries in freight train aerodynamic performance simulations Alexandria Engineering Journal Freight train Open track IDDES Periodic boundary Flow field Aerodynamic resistance |
| title | Application of periodic boundaries in freight train aerodynamic performance simulations |
| title_full | Application of periodic boundaries in freight train aerodynamic performance simulations |
| title_fullStr | Application of periodic boundaries in freight train aerodynamic performance simulations |
| title_full_unstemmed | Application of periodic boundaries in freight train aerodynamic performance simulations |
| title_short | Application of periodic boundaries in freight train aerodynamic performance simulations |
| title_sort | application of periodic boundaries in freight train aerodynamic performance simulations |
| topic | Freight train Open track IDDES Periodic boundary Flow field Aerodynamic resistance |
| url | http://www.sciencedirect.com/science/article/pii/S1110016823001473 |
| work_keys_str_mv | AT gaopengliang applicationofperiodicboundariesinfreighttrainaerodynamicperformancesimulations AT tanghongliu applicationofperiodicboundariesinfreighttrainaerodynamicperformancesimulations AT yutaoxia applicationofperiodicboundariesinfreighttrainaerodynamicperformancesimulations AT zhengweichen applicationofperiodicboundariesinfreighttrainaerodynamicperformancesimulations AT xiaodong applicationofperiodicboundariesinfreighttrainaerodynamicperformancesimulations AT xiaodongchen applicationofperiodicboundariesinfreighttrainaerodynamicperformancesimulations |