Unsteady Aerodynamic Characteristics of a High-Speed Train Induced by the Sudden Change of Windbreak Wall Structure: A Case Study of the Xinjiang Railway

Chen, Zheng-Wei; Rui, En-Ze; Liu, Tanghong; Ni, Yiqing; Huo, Xiaoshuai; Xia, Yonghong; Li, Wenhui; Guo, Zhancheng; Zhou, Lei

doi:10.3390/app12147217

Cited by 11 publications

(5 citation statements)

References 44 publications

(46 reference statements)

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“…The gradient of the scalar at the cell center is computed using the Green-Gauss method. In order to solve the pressure and velocity coupling equations, the semi-implicit method for the pressure-linked equations (SIMPLE) algorithm is utilized [32][33][34]. The second-order upwind scheme and bounded central differencing scheme are used [35], respectively, for k − ω equations and the momentum equation.…”

Section: Methodsmentioning

confidence: 99%

Aerodynamic Features of High-Speed Maglev Trains with Different Marshaling Lengths Running on a Viaduct under Crosswinds

Huang,

Zhou,

Chang

et al. 2024

CMES

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The safety and stability of high-speed maglev trains traveling on viaducts in crosswinds critically depend on their aerodynamic characteristics. Therefore, this paper uses an improved delayed detached eddy simulation (IDDES) method to investigate the aerodynamic features of high-speed maglev trains with different marshaling lengths under crosswinds. The effects of marshaling lengths (varying from 3-car to 8-car groups) on the train's aerodynamic performance, surface pressure, and the flow field surrounding the train were investigated using the three-dimensional unsteady compressible Navier-Stokes (N-S) equations. The results showed that the marshaling lengths had minimal influence on the aerodynamic performance of the head and middle cars. Conversely, the marshaling lengths are negatively correlated with the time-average side force coefficient (C S ) and time-average lift force coefficient (C l ) of the tail car. Compared to the tail car of the 3-car groups, the C S and C l fell by 27.77% and 18.29%, respectively, for the tail car of the 8-car groups. It is essential to pay more attention to the operational safety of the head car, as it exhibits the highest time average C S . Additionally, the mean pressure difference between the two sides of the tail car body increased with the marshaling lengths, and the side force direction on the tail car was opposite to that of the head and middle cars. Furthermore, the turbulent kinetic energy of the wake structure on the windward side quickly decreased as marshaling lengths increased.

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Section: Methodsmentioning

confidence: 99%

Aerodynamic Features of High-Speed Maglev Trains with Different Marshaling Lengths Running on a Viaduct under Crosswinds

Huang,

Zhou,

Chang

et al. 2024

CMES

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“…The simulation results were in good arrangement with those of the wind tunnel test. It needs to note that the transition region studied in this paper actually is one part of the Lanzhou–Xinjiang railway in China, and the wind speed in this region is about 35 m/s (Chen et al , 2021; Chen and Ni, 2022; Chen et al , 2022). Thus, to provide reference for the safety of train operation in this area, the freestream of baseline case was set as 35 m/s in the simulation ( Re = 8.87 × 10 6 ).…”

Section: Numerical Simulation Detailsmentioning

confidence: 99%

“…In fact, the most direct method to provide useful information for the safety of train operation is to study the variation of flow field around the train and its aerodynamic force as the train passes through the transition section under crosswinds, as our previous work reported (Chen et al , 2022). It is worth mentioning that the previous work on transition regions in windbreaks has provided various insights into this critical issue.…”

Section: Introductionmentioning

confidence: 99%

Impact of the windbreak transition on flow structures of the high-speed railway and mitigation using oblique structure and circular curve structure transition

Chen

Zeng

Hashmi

et al. 2023

HFF

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Purpose This paper aims to investigate the variations in the flow fields induced by transition regions in the windbreak structures between the flat ground and the cutting along a railway and to propose mitigation measures to improve the windproof ability of the windbreak. Design/methodology/approach The improved delayed detached eddy simulation method was used to simulate the impact of the windbreak transition on flow structures of the high-speed railway under different wind angles, and also the accuracy of the numerical results was validated with those of the wind tunnel test. Findings The results showed that the original windbreak transition region resulted in a dimensionless peak wind velocity of 0.62 and 0.82 for railway line-1 at wind angles of 90° and 75°, respectively, and the corresponding values were 0.81 and 0.97 for railway line-2. The flow structure analysis revealed the reason for the mismatched height in the transition region, and the right-angle structures of the windbreaks resulted in ineffective protection and sudden changes in the wind speed and direction. Two mitigation measures – oblique structure (OS) and circular curve structure (CCS) transition walls – were developed to reduce the peak wind speed. The OS provided superior protection. The peak value of dimensionless wind velocity was all less than 0.2 for OS and CCS. Originality/value The flow field deterioration mechanism induced by the inappropriate form of a windbreak transition at different wind angles was examined, and effective mitigation and improvement measures were proposed and compared with the original transition.

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“…Establishing an intercity railway system that matches the development of regional cities becomes an indispensable part of modern urban agglomerations and an important part of promoting regional economic development (Zhang et al , 2020). While increasing the running speed of trains brings convenience to intercity commuting, a series of operational safety problems will also become more prominent (Yang et al , 2019; Zhou et al , 2020; Chen et al , 2022b; Liu et al , 2022; Niu et al , 2022). In a complex crosswind environment, such as an embankment or viaduct, the train’s aerodynamic performance and index of operational safety will change dramatically (Diedrichs et al , 2007; Li et al , 2011a; Giappino et al , 2016; Baker and Sterling, 2018; Zhang et al , 2018; Li et al , 2022a; Yang et al , 2022), which seriously threatens the stability, safety and ride comfort of the train’s operation (Avila-Sanchez et al , 2017; Chen et al , 2018; Chen et al , 2019a; Jin et al , 2020; Chen et al , 2021).…”

Section: Introductionmentioning

confidence: 99%

Influence of wind and rain environment on operational safety of intercity train running on the viaduct

Zeng

Huang

et al. 2023

HFF

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Purpose Based on the aerodynamic loads and dynamic performances of trains, this study aims to investigate the effect of crosswinds and raindrops on intercity trains operating on viaducts to ensure the safe operation of intercity railways in metropolitan areas. Design/methodology/approach An approach coupled with the Euler multiphase model as well as the standard k-ɛ turbulence model is used to investigate the coupled flow feature surrounding trains and viaducts, including airflow and raindrops, and the numerical results are validated with those of the wind tunnel test. Additionally, the train’s dynamic response and the operating safety region in different crosswind speeds and rainfall is investigated based on train’s aerodynamic loads and the train wheel–rail dynamics simulation. Findings The aerodynamic loads of trains at varying running speeds exhibit an increasing trend as the increase of wind speed and rainfall intensity. The motion of raindrop particles demonstrates a significant similarity with the airflow in wind and rain environments, as a result of the dominance of airflow and the supplementary impacts of droplets. As the train’s operating speed ranged between 120 and 200 km/h and within a rainfall range of 20–100 mm/h, the safe operating region of trains decreased by 0.56%–7.03%, compared with the no-rain condition (0 mm/h). Originality/value The impact of crosswind speeds and rainfall on the train’s aerodynamic safety is studied, including the flow feature of crosswind and different particle-sized raindrops around the train and viaduct, aerodynamic loads coefficients suffered by the intercity train as well as the operating safety region of intercity trains on the viaduct.

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Unsteady Aerodynamic Characteristics of a High-Speed Train Induced by the Sudden Change of Windbreak Wall Structure: A Case Study of the Xinjiang Railway

Cited by 11 publications

References 44 publications

Aerodynamic Features of High-Speed Maglev Trains with Different Marshaling Lengths Running on a Viaduct under Crosswinds

Aerodynamic Features of High-Speed Maglev Trains with Different Marshaling Lengths Running on a Viaduct under Crosswinds

Impact of the windbreak transition on flow structures of the high-speed railway and mitigation using oblique structure and circular curve structure transition

Influence of wind and rain environment on operational safety of intercity train running on the viaduct

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