Open Access
ARTICLE
Yundong Han1, Dawei Chen1, Shaoqing Liu1, Gang Xu2
FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.1, pp. 1-19, 2020, DOI:10.32604/fdmp.2020.06525
(This article belongs to this Special Issue: Train Aerodynamics)
Abstract A series of tests have been conducted using a Cryogenic Wind Tunnel to study
the effect of Reynolds number (Re) on the aerodynamic force and surface pressure
experienced by a high speed train. The test Reynolds number has been varied from 1
million to 10 million, which is the highest Reynolds number a wind tunnel has ever
achieved for a train test. According to our results, the drag coefficient of the leading car
decreases with higher Reynolds number for yaw angles up to 30º. The drag force
coefficient drops about 0.06 when Re is raised from 1 million to 10… More >
Open Access
ARTICLE
Jiali Liu1, Mengge Yu2, *, Dawei Chen1, Zhigang Yang3
FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.1, pp. 21-30, 2020, DOI:10.32604/fdmp.2020.07658
(This article belongs to this Special Issue: Train Aerodynamics)
Abstract In order to investigate how the aerodynamic drag and noise produced by the
roof air conditioner of a high-speed train can be reduced, the related unsteady flow in the
near-field was computed using the method of large eddy simulation. In this way, the
aerodynamic source for noise generation has initially been determined. Then, the far-field
aerodynamic noise has been computed in the framework of the Lighthill’s acoustics
analogy theory. The propulsion height and flow-guide angle of the roof air conditioner
were set as the design variables. According to the computational results, a lower
propulsion height or flow-guide angle is beneficial… More >
Open Access
ARTICLE
Zhiyuan Dai1, Tian Li1, *, Weihua Zhang1, Jiye Zhang1
FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.1, pp. 31-40, 2020, DOI:10.32604/fdmp.2020.07661
(This article belongs to this Special Issue: Train Aerodynamics)
Abstract Pantograph is a critical component of the high-speed train. It collects power
through contact with catenary, which significantly affects the running safety of the train.
Pantograph with double collector strips is one common type. The aerodynamic
performance of the collector strips may affect the current collection of the pantograph. In
this study, the aerodynamic performance of the pantograph with double strips is
investigated. The numerical results are consistent with the experimental ones. The error
in the aerodynamic drag force of the pantograph between numerical and experimental
results is less than 5%. Three different conditions of the strips are studied, including… More >
Open Access
ARTICLE
Lu Cai1, Zhen Lou1, Nan Liu2, Chao An2, Jiye Zhang1, *
FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.1, pp. 41-53, 2020, DOI:10.32604/fdmp.2020.07731
(This article belongs to this Special Issue: Train Aerodynamics)
Abstract To investigate the deposition distribution of snow particles in the bogie
surfaces of a high-speed train, a snow particle deposition model, based on the critical
capture velocity and the critical shear velocity, was elaborated. Simulations based on the
unsteady Reynolds-Averaged Navier-Stokes (RANS) approach coupled with Discrete
Phase Model (DPM) were used to analyze the motion of snow particles. The results show
that the cross beam of the bogie frame, the anti-snake damper, the intermediate brake
clamps in the rear wheels, the traction rod and the anti-rolling torsion bar are prone to
accumulate snow. The accumulation mass relating to the vertical… More >
Open Access
ARTICLE
Mengge Yu1, 2, Zhenkuan Pan3, *, Jiali Liu4, Haiqing Li1
FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.1, pp. 55-66, 2020, DOI:10.32604/fdmp.2020.07774
(This article belongs to this Special Issue: Train Aerodynamics)
Abstract The operational safety characteristics of trains exposed to a strong wind have
caused great concern in recent years. In the present paper, the effect of the strong gust
wind on a high-speed train is investigated. A typical gust wind model for any wind angle,
named “Chinese hat gust wind model”, was first constructed, and an algorithm for
computing the aerodynamic loads was elaborated accordingly. A vehicle system dynamic
model was then set up in order to investigate the vehicle system dynamic characteristics.
The assessment of the operational safety has been conducted by means of characteristic
wind curves (CWC). As some… More >
Open Access
ARTICLE
Xiaohan Zhang1, Yao Jiang2, Tian Li1, *
FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.1, pp. 67-76, 2020, DOI:10.32604/fdmp.2020.07776
(This article belongs to this Special Issue: Train Aerodynamics)
Abstract The aerodynamic resistance of a train running in the open air limits the maximum
speed that can be attained by the train. For this reason, evacuated tube trains (ETT) are being
considered as valid alternatives to be implemented in the future. The atmosphere in the tube,
the so-called blocking ratio and the length of the streamlined nose are the key factors affecting
the aerodynamic performances of these trains. In the present work, we investigate evacuated
tube trains with different lengths of the streamline nose on the basis of computational fluid
dynamics (CFD). The three-dimensional steady compressible Navier-Stokes equations are
solved.… More >
Open Access
ARTICLE
Haiqing Li1, Mengge Yu1, *, Qian Zhang1, Heng Wen1
FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.1, pp. 77-90, 2020, DOI:10.32604/fdmp.2020.07797
(This article belongs to this Special Issue: Train Aerodynamics)
Abstract The performances of high-speed trains in the presence of coupling effects with
crosswind and rain have attracted great attention in recent years. The objective of the
present paper was to investigate the aerodynamic characteristics of a high-speed train under
such conditions in the framework of an Eulerian-Lagrangian approach. An aerodynamic
model of a high-speed train was first set up, and the side force coefficient obtained from
numerical simulation was compared with that provided by wind tunnel experiments to
verify the accuracy of the approach. Then, the effects of the yaw angle, the resultant wind
speed, and the rainfall rate on… More >
Open Access
ARTICLE
D. O. Redchyts1, E. A. Shkvar2, *, S. V. Moiseienko3
FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.1, pp. 91-103, 2020, DOI:10.32604/fdmp.2020.07933
(This article belongs to this Special Issue: Train Aerodynamics)
Abstract A method to evaluate the properties of turbulent flow in proximity to the vehicle
and close to the ground surface has been elaborated. Numerical simulations have been
performed on the basis of the Unsteady Reynolds-averaged Navier-Stokes equations
(URANS) written with respect to an arbitrary curvilinear coordinate system. These
equations have been solved using the Spalart-Allmaras differential one-parametric
turbulence model. The method of artificial compressibility has been used to improve the
coupling of pressure and velocity in the framework of a finite volume approach. Time-averaged distributions of pressure fields, velocity components, streamlines in the entire area
and near the tractor-trailer, as… More >
Open Access
ARTICLE
Yadong Zhang1, *, Jiye Zhang2
FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.1, pp. 105-120, 2020, DOI:10.32604/fdmp.2020.07959
(This article belongs to this Special Issue: Train Aerodynamics)
Abstract The object of research of this paper is the DSA380 high-speed pantograph. The
near-field unsteady flow around the pantograph was investigated using large eddy
simulation (LES) while the far-field aerodynamic noise was analysed in the frame of the
Ffowcs Williams-Hawkings (FW-H) acoustic analogy. According to the results, the contact
strip, base frame and knuckle are the main aerodynamic noise sources, with vortex shedding,
flow separation and recombination around the pantograph being related key physical factors.
The aerodynamic noise radiates outwards in the form of spherical waves when the distance
of the noise receiving point is farther than 8 m. The… More >
Open Access
ARTICLE
Tian Li1, *, Xiaohan Zhang1, Yao Jiang2, Weihua Zhang1
FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.1, pp. 121-130, 2020, DOI:10.32604/fdmp.2020.07976
(This article belongs to this Special Issue: Train Aerodynamics)
Abstract The so-called Evacuated Tube Train (ETT) is currently being proposed as a
high-speed transportation system potentially competitive with airplane transportation.
Aerodynamic resistance is one of the most crucial factors for the successful design of an
ETT. In the present work, a three-dimensional concept ETT model has been elaborated.
The aerodynamic characteristics of the subsonic ETT have been numerically simulated
under different conditions. The train’s running speed varies from 600 km/h up to 1200
km/h, and the blockage ratio is in the range between 0.1 and 0.3. As the blocking ratio
and running speed increase, the resistance of the head car… More >