Optimization of Bridge Windbreak on High-Speed Railway through Strong Wind Area

2012 ◽  
Vol 452-453 ◽  
pp. 1518-1521 ◽  
Author(s):  
Ling Ling Zhou ◽  
Xi Feng Liang ◽  
Ming Zhi Yang ◽  
Sha Huang

Based on 3-d, uncompressible onflow model with steady N-S equation and the k-epsilon double equation, aerodymic characteristics of EMU and windbreaks on bridge under cross wind were studied numerically, the results show: (1) compared to no windbreak, EMU overturning moment was decreased 50% by setting general windbreak , 75% by setting ventilated windbreak; ventilated windbreak’s protective effect on train and pantograph-catenary system is better especially when H≥2.5m ; (2) aerodynamic load on ventilated windbreak is far lower than general windbreak; (3)the higher cross-wind velocity is, the more aerodynamic load decreased when setting ventilated windbreak. Besides, ventilated windbreak’s leak form could significantly reduce bridge’s self gravity and wind load, improve wind break ability and EMU operation safety.

2019 ◽  
Vol 22 (15) ◽  
pp. 3306-3318
Author(s):  
Wanmin Ren ◽  
Qingsong Duan ◽  
Cunming Ma ◽  
Haili Liao ◽  
Qiusheng Li

This study aims to investigate the wind protective effect of wind barriers on the Lanzhou–Xinjiang high-speed railway using wind tunnel tests. Wind barriers with different heights and porosities were analyzed. Two girders, that is, a box-girder and a trough-girder, each with 1:30 and 1:8 scales were experimentally investigated. The results suggest that the protective effect of the wind barrier with a height of 4 m and porosity of 20% is better than the others. The influence of wind barriers on the aerodynamic characteristics of train vehicles and girders must be analyzed simultaneously. The aerostatic force coefficients of trains are approximately the same at different scales, and the Reynolds number effect could be neglected.


2018 ◽  
Vol 91 ◽  
pp. 496-506 ◽  
Author(s):  
Xi-Yang Liu ◽  
Jin-Fang Peng ◽  
De-Qiang Tan ◽  
Zhi-Biao Xu ◽  
Jian-Hua Liu ◽  
...  

2018 ◽  
Vol 15 (3) ◽  
pp. 172988141877394 ◽  
Author(s):  
Ye Han ◽  
Zhigang Liu ◽  
DJ Lee ◽  
Wenqiang Liu ◽  
Junwen Chen ◽  
...  

Maintenance of catenary system is a crucial task for the safe operation of high-speed railway systems. Catenary system malfunction could interrupt railway service and threaten public safety. This article presents a computer vision algorithm that is developed to automatically detect the defective rod-insulators in a catenary system to ensure reliable power transmission. Two key challenges in building such a robust inspection system are addressed in this work, the detection of the insulators in the catenary image and the detection of possible defects. A two-step insulator detection method is implemented to detect insulators with different inclination angles in the image. The sub-images containing cantilevers and rods are first extracted from the catenary image. Then, the insulators are detected in the sub-image using deformable part models. A local intensity period estimation algorithm is designed specifically for insulator defect detection. Experimental results show that the proposed method is able to automatically and reliably detect insulator defects including the breakage of the ceramic discs and the foreign objects clamped between two ceramic discs. The performance of this visual inspection method meets the strict requirements for catenary system maintenance.


2013 ◽  
Vol 307 ◽  
pp. 149-155
Author(s):  
Hong Chao Wang ◽  
Jin Fa Xie

Based on the model, it firstly gets the fluid distribution of noise barrier of high-speed railway, which is under the action of train-induced impulsive wind pressure and natural wind load, then transfers the computed result as exported load to the structural analysis module through the coupling interface, by proceeding the transient dynamic analysis and modal analysis, it finally obtains the equivalent stress, total deformation and modal distribution of noise barrier. The results indicate that, compared with train-induced impulsive wind pressure, the natural wind load has a more obvious effect on the structural performance of noise barrier, and its natural frequency is much less than the external load’s, so there will be no resonate happen in practice.


2018 ◽  
Vol 18 (07) ◽  
pp. 1850093 ◽  
Author(s):  
Xiao-Hui Zeng ◽  
Jiang Lai ◽  
Han Wu

With the rising speed of high-speed trains, the aerodynamic loads become more significant and their influences on the hunting stability of railway vehicles deserve to be considered. Such an effect cannot be properly considered by the conventional model of hunting stability analysis. To this end, the linear hunting stability of high-speed railway vehicles running on tangent tracks is studied. A model considering the steady aerodynamic loads due to the joint action of the airflow facing the moving train and the crosswind, is proposed for the hunting stability analysis of a railway vehicle with 17 degrees of freedom (DOF). The key factors considered include: variations of the wheel–rail normal forces, creep coefficients, gravitational stiffness and angular stiffness due to the actions of the aerodynamic load, which affects the characteristics of hunting stability. Using the computer program developed, numerical calculations were carried out for studying the behavior of the linear hunting stability of vehicles under steady aerodynamic loads. The results show that the aerodynamic loads have an obvious effect on the linear critical speeds and instability modes. The linear critical speed decreases monotonously as the crosswind velocity increases, and the influences of pitch moment and lift force on the linear critical speed are larger than the other components of the aerodynamic loads.


2007 ◽  
Vol 347 ◽  
pp. 365-372 ◽  
Author(s):  
Seong Wook Lee ◽  
Tae Won Ahn ◽  
Dong Seop Han ◽  
Tae Hyung Kim ◽  
Geun Jo Han

In this study we carried out to analyze the effect of wind load on the structural stability of a container crane according to the change of the boom shape using wind tunnel test and provided a container crane designer with data which can be used in a wind resistance design of a container crane assuming that a wind load at 75m/s wind velocity is applied on a container crane. Data acquisition conditions for this experiment were established in accordance with the similarity. The scale of a container crane dimension, wind velocity and time were chosen as 1/200, 1/13.3 and 1/15. And this experiment was implemented in an Eiffel type atmospheric boundary-layer wind tunnel with 11.52m2 cross-section area. Each directional drag and overturning moment coefficients were investigated.


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