Experimental study on the effect of wind angles on pressure distribution of train streamlined zone and train aerodynamic forces

Zhang, Lei; Yang, Mingzhi; Liang, Xifeng

doi:10.1016/j.jweia.2018.01.024

Cited by 90 publications

(43 citation statements)

References 41 publications

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“…The Reynolds number in this study is from 9.69 × 10 5 (corresponding to 250 km/h) to 1.36 × 10 6 (corresponding to 350 km/h) and that of the real train is from 1.94 × 10 7 to 2.71 × 10 7 . According to the EN Standard 14067–4 [32], when the Reynolds number of the scaled model test is larger than 2.5 × 10 5 , the aerodynamics coefficients are nearly invariable with increasing Reynolds numbers [27,30,31,33]. As a result, the results of moving model tests of simulating a real train passing through a tunnel is reliable and the aerodynamics coefficients of moving model tests can represent that of the real train.…”

Section: Methodsmentioning

confidence: 99%

Risks of Ear Complaints of Passengers and Drivers While Trains Are Passing Through Tunnels at High Speed: A Numerical Simulation and Experimental Study

Xie

Peng

Wang

et al. 2019

IJERPH

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Ear complaints induced by interior pressure transients are common experiences for passengers and crew members when high-speed trains are passing through tunnels. However, approaches to assessing the risks of the pressure-related aural discomfort have not been reported until recently. The objective of this study was to evaluate the hazards of interior pressure transients of high-speed train on human ears combining the effects of operation speed and seal index. Moving model tests were conducted to obtain the pressure transients when the model train runs in the tunnel. The recorded data were transformed into the interior pressures by empirical formula. Furthermore, the aural sensations were divided into four levels hierarchically and the range for each level was derived by logistic regression analysis method and represented by three biomechanical metrics. Furthermore, a human middle ear finite element (FE) model was used to simulate its dynamics under the interior pressures. The results indicate that lifting operation speed from 250 km/h to 350 km/h in tunnel will prolong the duration of ear complaints by more than two times whereas improving the seal index from 4 s to 12 s will reduce the incidences of the onset of tinnitus and hearing loss by more than ten times. In addition, the duration of aural comfort shortens from the head car to the tail car against the running direction. It is desirable that enhancing the seal index improve the aural sensations of the passengers and crew members considering the lifting operation speed of high-speed train.

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Section: Methodsmentioning

confidence: 99%

Risks of Ear Complaints of Passengers and Drivers While Trains Are Passing Through Tunnels at High Speed: A Numerical Simulation and Experimental Study

Xie

Peng

Wang

et al. 2019

IJERPH

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“…A wind tunnel test on the aerodynamic drag of the high-speed train has been carried out in the Low Speed Aerodynamic Institute of China Aerodynamics Research & Development Center (CARDC). The detail information about the wind tunnel test can be found from Zhang and Zhou (2013) and Zhang et al (2018b). To validate the resolution of the mesh and the methodology used in this paper, the same geometry, blockage ratio, and inlet conditions were simulated in the verified case.…”

Section: Program Validationmentioning

confidence: 99%

Effect of Two Bogie Cavity Configurations on the Underbody Flow and Near Wake Structures of a High-Speed Train

Zhang

et al. 2019

JAFM

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A time-dependent simulation method, DES (detached eddy simulation), combined with Realizable k-ε turbulence model, has been adopted to study the underbody flow and near wake structures of a high-speed train with two bogie cavity configurations laid on the stationary ground. The numerical data, including timeaveraged aerodynamic drag forces and pressure coefficients, were compared with experimental results from previous wind tunnel tests. A detail comparison of the instantaneous flow structures, mean velocity vector contours, velocity and pressure profiles under the train bottom in the symmetry plane and velocity contours overlaid with streamlines in the wake has been conducted in the two configurations. Also the aerodynamic drag coefficients for the two cases are discussed herein. The two cases show that the bogie cavity configurations contribute to the differences of velocity and pressure distributions in each bogie region, as well as the complex vortex structures around the bogie regions. Compared to the inclined bogie cavity configuration, the train with straight plates experiences a lower drag force by 2.8% for a three-car model in the stationary ground. Thus, an effective simplification criterion for the train model will contribute to an accurate prediction of forces of trains in simulations.

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“…Concerns regarding the driving safety and comfort of trains running on bridges under high crosswinds are highlighted. Many researchers have carried out a large number of studies on the wind-induced safety issues of trains (Baker, 2010(Baker, , 2013Cheli et al, 2012;He et al, 2018;Li et al, 2019;Rocchi et al, 2018;Zhang et al, 2018). However, these existing studies are far from sufficient.…”

Section: Introductionmentioning

confidence: 99%

Effect of unsteady aerodynamic loads on driving safety and comfort of trains running on bridges

Han

Liu

Peng

et al. 2020

Advances in Structural Engineering

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In order to investigate the effects of unsteady aerodynamic loads on the driving safety and comfort of trains running on bridges, a three-dimensional and multi-body system model of train–track–bridge was established and the dynamic responses of the coupling system were calculated by combining the finite element software ANSYS with the multi-body dynamics software SIMPACK. The driving safety and comfort of a train running on a bridge under steady and unsteady aerodynamic loads were compared and analyzed. The effects of different crosswind speeds on the driving safety of the train running on the bridge under unsteady aerodynamic loads were studied. It is found that the index values of the driving safety and comfort of the train at the speed of 200–300 km/h without the wind loads are smaller (meaning safer) than those of the train under the wind loads. When the average speed of crosswind is 20 m/s, the driving safety assessment results of the train are better and its comfort assessment results are more conservative with considering the unsteady aerodynamic loads than the steady wind load case. When the average speed of crosswind is smaller than 10 m/s and the train speed is 250 km/h, the driving safety and comfort of the train on the bridge meet the requirements, and the level of stability can reach “good” or above. Through the analysis of driving safety of the train on the bridge under different crosswind speeds, the threshold values of safe driving were obtained, which can provide a better basis for the safe operation of trains on bridges.

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Experimental study on the effect of wind angles on pressure distribution of train streamlined zone and train aerodynamic forces

Cited by 90 publications

References 41 publications

Risks of Ear Complaints of Passengers and Drivers While Trains Are Passing Through Tunnels at High Speed: A Numerical Simulation and Experimental Study

Risks of Ear Complaints of Passengers and Drivers While Trains Are Passing Through Tunnels at High Speed: A Numerical Simulation and Experimental Study

Effect of Two Bogie Cavity Configurations on the Underbody Flow and Near Wake Structures of a High-Speed Train

Effect of unsteady aerodynamic loads on driving safety and comfort of trains running on bridges

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