Optimization Analysis of Height and Distance for Shelter Wind Wall of High Speed Railway

2012 ◽  
Vol 588-589 ◽  
pp. 1794-1800 ◽  
Author(s):  
Kun Ye ◽  
Ren Xian Li
Keyword(s):  
Numerical Analysis ◽  
High Speed ◽  
Three Dimensional ◽  
Aerodynamic Forces ◽  
Optimization Analysis ◽  
High Speed Railway ◽  
Rolling Moment ◽  
Side Force ◽  
Wind Speeds ◽  
Simulation Results

Shelter wind wall is one of the most effective devices to reduce crosswind loads acting on trains. The height of the wall and distance between the wall and the center of railway are important factors for design and construction of wind wall. Since the wall design is related to many factors, such as train speeds, transverse wind speeds, types of the wall and so on, up to now, there are still different judgment methods in the optimal height and distance of the wall to get minimum aerodynamic forces on the train. Based on numerical analysis methods of three-dimensional viscous compressible aerodynamics equations, aerodynamic side forces and rolling moments acting on the train are analyzed. With 275 calculation models, include the straight and different radius curve railway with different heights and distances of shelter wind wall, the aerodynamic side forces and rolling moments are calculated. Simulation results show that the optimal height and distance of the wall are not the same during in straight and curve railway. And the direction of aerodynamic side force and rolling moment acting on the head and rear train may be different. The change trends of transverse forces (moments) with the height and distance of the wall are also different.

Aerodynamic Characteristics Analysis of High-Speed Train on Cutting under Crosswinds

2013 ◽  
Vol 300-301 ◽  
pp. 62-67
Author(s):  
Kun Ye ◽  
Ren Xian Li
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Aerodynamic Characteristics ◽  
High Speed Train ◽  
Aerodynamic Forces ◽  
Cutting Depth ◽  
Cutting Slope ◽  
Characteristics Analysis ◽  
Relationship Of ◽  
The Relationship

Cutting is an effective device to reduce crosswind loads acting on trains. The cutting depth, width and gradient of slope are important factors for design and construction of cutting. Based on numerical analysis methods of three-dimensional viscous incompressible aerodynamics equations, aerodynamic side forces and yawing moments acting on the high-speed train, with different depths and widths of cutting，are calculated and analyzed under crosswinds，meanwhile the relationship of the gradient of cutting slope and transverse aerodynamic forces acting on trains are also studied. Simulation results show that aerodynamic side forces and yawing moments acting on the train（the first, middle and rear train）decrease with the increase of cutting depth. The relationship between transverse forces (moments) coefficients acting on the three sections and the cutting depth basically is the three cubed relation. The bigger is cutting width，the worse is running stability of train. The relationship between yawing moments coefficients acting each body of the train and the cutting width approximately is the three cubed relation. The transverse Aerodynamic forces decreased gradually with the increase of the gradient of cutting slope, the relationship between yawing moments coefficients acting each body of the train and the gradient of cutting slope basically is the four cubed relation.

scholarly journals Numerical studies on aerodynamics of high-speed railway train subjected to strong crosswind

2019 ◽  
Vol 11 (11) ◽  
pp. 168781401988727
Author(s):  
Xu Wang ◽  
Yuanhao Qian ◽  
Zengshun Chen ◽  
Xiao Zhou ◽  
Huaqiang Li ◽  
...  
Keyword(s):  
Wind Speed ◽  
High Speed ◽  
Lift Coefficient ◽  
Aerodynamic Characteristics ◽  
Width Ratio ◽  
Force Coefficient ◽  
Rolling Moment ◽  
Side Force ◽  
Train Speed ◽  
Yaw Angle

Under the action of strong crosswind, the aerodynamic behavior of a rail vehicle at high speed will be changed significantly, which could directly affect the safe operation of the vehicle. With the help of the shape of train used in China, the aerodynamic characteristics of trains with scale of 1:1 is investigated using computational fluid dynamics numerical simulation method, which consists of the variation of aerodynamics force and moment with wind yaw angle, wind speed, train speed, and nose shape. After an initial validation against Baker’s results from wind tunnel test, the numerical model is then used to investigate the aerodynamic characteristics of the trains. The numerical results indicate that lift coefficient of the M train is slightly higher than TMC1 and TMC2 trains. Regardless of aerodynamics force coefficients, TMC1 reaches the maximum at a yaw angle of 75°. Aerodynamics force coefficient increases with both wind speed and train speed, but the change of which is not linear. Comparing aerodynamic force with different geometric dimensions of train nose, it is shown that height–width ratio is insensitive to side force and rolling moment, but sensitive to lift force from the yaw angle 0°–90°. The side force coefficient, as we most concern, is less than other results, when the length–width ratio is 1 and height–width is 0.87.

Study on Rolling Contact Behaviors of Three Kinds of Railway Wheel Treads

2010 ◽  
Vol 118-120 ◽  
pp. 151-155
Author(s):  
Wen Jian Wang ◽  
Qing Fei Zeng ◽  
Jun Guo ◽  
Qi Yue Liu
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Comprehensive Analysis ◽  
Rolling Contact ◽  
Contact Theory ◽  
Matching Effect ◽  
High Speed Railway ◽  
Railway Wheel ◽  
Elastic Bodies ◽  
Numerical Program

The rolling contact behaviors between LMA, S1002 and XP55 wheelset and track in static rolling contact are analyzed using the rolling contact theory of three-dimensional elastic bodies with non-Hertz form and numerical program of CONTACT. The numerical results indicate that three kinds of wheel treads have different difference of rolling radius and equivalent taper. The rolling contact behaviors between three kinds of wheel treads and CHN60 rail have obvious difference. The comprehensive analysis indicates that the matching effect of LAM wheel tread and CHN60 rail is relatively superior. Furthermore, it is suggested that new wheel tread should be designed and optimized for the high-speed railway.

scholarly journals Study on the Calculation Method of the Diffusion Range of Grouting Slurry for a High-speed Railway Ballastless Track Subgrade

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Changwei Yang ◽  
Jinhao Guo ◽  
Shaowei Wei ◽  
Liang Zhang ◽  
Sifeng Li ◽  
...  
Keyword(s):  
High Speed ◽  
Theoretical Study ◽  
Early Stage ◽  
Soil Mass ◽  
High Speed Railway ◽  
Grouting Pressure ◽  
Diffusion Curve ◽  
Practical Engineering ◽  
Simulation Results ◽  
Diffusion Form

Grouting engineering is the most convenient and quick way to deal with postconstruction settlement. Based on the investigation of the Beijing Shenyang high-speed railway in the early stage, the microdestructive force of grout on the soil mass in the process of grouting with the method of fluid solid coupling theory was analyzed. The numerical simulation results show that, in the grouting process, the greater the grouting pressure, the wider the diffusion range of the slurry and the greater the damage to the microscopic contact force of the slurry to the soil; in addition, when the grouting pressure is below 0.15 MPa, the diffusion form of the slurry in the soil is osmotic grouting; when the pressure is about 0.3 MPa, the diffusion form of the slurry in the soil is compacted grouting; on the basis of the simulation results, a deeper research is carried out, and the calculation formula of the slurry diffusion curve is obtained. It fills in the blank of the theoretical study of the slurry diffusion curve. In this paper, the diffusion formula of grouting slurry can be used in the theoretical study of clay grouting, and it can be used as a reference for practical engineering.

scholarly journals Dynamic Analysis of a High-Speed Railway Train With the Defective Axle Bearing

2020 ◽  
Vol 25 (4) ◽  
pp. 525-531
Author(s):  
Jing Liu ◽  
Shangkun Du
Keyword(s):  
Dynamic Analysis ◽  
High Speed ◽  
Time Dependent ◽  
Force Model ◽  
High Speed Railway ◽  
The Road ◽  
Reasonable Approach ◽  
Simulation Results ◽  
Train System ◽  
Track Irregularities

Axle bearings (AXBs) are critical parts for high-speed railway trains (HSTs). Local faults in the AXBs have great influences on the operational dynamics of HSTs. Although some previous works formulated the local faults in single AXB, the vibrations of the whole train system with the defective AXB cannot be described. To overcome this problem, this study conducts a dynamic model for a HST considering a local fault in one AXB. The previous single AXB model cannot formulate the studied case. The impacts caused by the fault in the AXB is defined as a time-dependent force model considering a half-sine type. The road spectrum excitations from the roadbed and rail are formulated by a track irregularities model. The effects of the train speeds and fault sizes on the HST dynamics are introduced. The simulation results from the proposed and previous works are contrasted to show the model validation. The results show that the faults in the AXB will greatly affect the HST dynamics. It depicts that this study can afford a more reasonable approach for understanding the dynamics of HSTs considering the defective AXBs compared to the reported single AXB model.

The Application of Three Dimensional Drainage Flexible and Ecological Reinforced Construction in High-Speed Railway Station Roadbed

2012 ◽  
Vol 594-597 ◽  
pp. 2025-2029
Author(s):  
An Hui Wang ◽  
Hong Sheng He
Keyword(s):  
High Speed ◽  
Retaining Wall ◽  
Three Dimensional ◽  
Railway Station ◽  
High Speed Railway ◽  
Retaining Structure ◽  
Technical Requirements ◽  
Reinforced Earth ◽  
Key Points ◽  
New Type

This paper introduced a new type of retaining structure in roadbed of a high-speed railway Station--Three dimensional Drainage Flexible and Ecological Reinforced Earth Retaining Wall. Both side efforts of this structure have taken into account in lope protection and environmental protection, so it can be promoted in high-speed railway construction. Its main advantages included: ecology, environment protection, simple construction method, the better adaptability to differential settlement, the better stability, and so on. This type of retaining structure mainly composed by geogrid, ecological bags, tying belts, connecting buckle, etc. In the construction should pay attention to the technical requirements of the laying of geogrid, the stacking of the eco-bags and placing of connecting buckle and so on. This paper discussed briefly of the type structure from its advantages, its compositions and its construction key points

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