Study on the pressure pipe length in train aerodynamic tests and its applications in crosswinds

Liu, Tanghong; Wang, Lei; Chen, Zhengwei; Gao, Hui; Li, Wenhui; Guo, Zhancheng; Xia, Yonghong; Huo, Xiaoshuai; Wang, You‐Wu

doi:10.1016/j.jweia.2021.104880

Cited by 15 publications

(5 citation statements)

References 49 publications

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“…If we denote the vector by W the weight of the aircraft and by the vector w the force of buoyancy, the total force due to gravity and buoyancy is W + w. We observe that the weight of an aircraft is a force with magnitude W whose direction is vertically downwards, while the force of buoyancy with magnitude w whose direction is vertically upwards so that the magnitude of the resultant force is W-w [7]. This force W + w will act whether the aircraft is at rest or in motion [8].…”

Section: Proceedings Of the 8 Th International Exchange And Innovatio...mentioning

confidence: 93%

Laminar Flow Analysis of NACA 4412 Airfoil Through ANSYS Fluent

Arif¹,

Afzal²,

Javaid³

et al. 2022

Proceedings of International Exchange and Innovation Conference on Engineering &Amp; Sciences (IEICES)

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Due to the consideration of less angle of attack in the Airfoil, the previous studies didn't achieve accurate results on velocity and pressure of air fluid. Also, previous studies haven't taken into account both the coefficients of drag and lift forces at the same time. In this study, first-time we used the NACA 4412 (national advisory committee for aeronautics 4412) Airfoil because of its availability, lightweight, and flat bottom surface which prevents negative ground effects. Here the NACA 4412 Airfoil surface characteristics were studied through ANSYS Fluent laminar flow analysis as well as pressure-based ANSYS fluent solver. When we increased the angle of attack from 0º to 18º the coefficients of lift and drag forces increase gradually, which impacts the values of the velocity of the upper surface and pressure of the lower surface in the air-fluid. The coefficient of lift and drag forces on the airfoil's surface were 0.44 and 0.5, while the velocity and pressure at the surface are 80.5354 ms -1 and 2.12 × 10 3 Pa respectively at a 16º angle.

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Section: Proceedings Of the 8 Th International Exchange And Innovatio...mentioning

confidence: 93%

Laminar Flow Analysis of NACA 4412 Airfoil Through ANSYS Fluent

Arif¹,

Afzal²,

Javaid³

et al. 2022

Proceedings of International Exchange and Innovation Conference on Engineering &Amp; Sciences (IEICES)

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show abstract

“…Strong crosswinds on railways cause more concerns, as they threaten both the comfort and safety of the trains, with accidents every year (Diedrichs et al , 2007; Baker et al , 2009). The research on the aerodynamics (Krajnović et al , 2012; Cui et al , 2014; Liu et al , 2022) and dynamics (Shao et al , 2011; Li et al , 2013; Liu et al , 2019) of train subjected to crosswind has attracted wide attention and has been investigated all over the world. To identify the aerodynamic characteristics of different trains under crosswind, trains with different shapes have been studied by scholars, for instance, German ICE2 (Hemida and Krajnović, 2009), China high-speed train (Gao et al , 2021) and double unit train (Guo et al , 2019).…”

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

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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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Study on the pressure pipe length in train aerodynamic tests and its applications in crosswinds

Cited by 15 publications

References 49 publications

Laminar Flow Analysis of NACA 4412 Airfoil Through ANSYS Fluent

Laminar Flow Analysis of NACA 4412 Airfoil Through ANSYS Fluent

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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