Search results

1 – 3 of 3
Per page
102050
Citations:
Loading...
Access Restricted. View access options
Article
Publication date: 25 July 2024

Wei-Chao Yang, Guo-Zhi Li, E Deng, De-Hui Ouyang and Zhi-Peng Lu

Sustainable urban rail transit requires noise barriers. However, these barriers’ durability varies due to the differing aerodynamic impacts they experience. The purpose of this…

75

Abstract

Purpose

Sustainable urban rail transit requires noise barriers. However, these barriers’ durability varies due to the differing aerodynamic impacts they experience. The purpose of this paper is to investigate the aerodynamic discrepancies of trains when they meet within two types of rectangular noise barriers: fully enclosed (FERNB) and semi-enclosed with vertical plates (SERNBVB). The research also considers the sensitivity of the scale ratio in these scenarios.

Design/methodology/approach

A 1:16 scaled moving model test analyzed spatiotemporal patterns and discrepancies in aerodynamic pressures during train meetings. Three-dimensional computational fluid dynamics models, with scale ratios of 1:1, 1:8 and 1:16, used the improved delayed detached eddy simulation turbulence model and slip grid technique. Comparing scale ratios on aerodynamic pressure discrepancies between the two types of noise barriers and revealing the flow field mechanism were done. The goal is to establish the relationship between aerodynamic pressure at scale and in full scale.

Findings

The aerodynamic pressure on SERNBVB is influenced by the train’s head and tail waves, whereas for FERNB, it is affected by pressure wave and head-tail waves. Notably, SERNBVB's aerodynamic pressure is more sensitive to changes in scale ratio. As the scale ratio decreases, the aerodynamic pressure on the noise barrier gradually increases.

Originality/value

A train-meeting moving model test is conducted within the noise barrier. Comparison of aerodynamic discrepancies during train meets between two types of rectangular noise barriers and the relationship between the scale and the full scale are established considering the modeling scale ratio.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 34 no. 9
Type: Research Article
ISSN: 0961-5539

Keywords

Access Restricted. View access options
Article
Publication date: 10 December 2019

Cong Ding, Zhen-Yu Zhou, Zhi-Peng Yuan, Hua Zhu and Zhong-Yu Piao

The purpose of this paper is to study the correlation between the dynamic features of the running-in attractor and the wear particle group, so as to characterize the running-in…

103

Abstract

Purpose

The purpose of this paper is to study the correlation between the dynamic features of the running-in attractor and the wear particle group, so as to characterize the running-in attractor by means of the wear particle group.

Design/methodology/approach

Wear particles are collected in phased wear experiments, and their dynamic features are investigated by the equivalent mean chord length L. Then, the correlation between the equivalent mean chord length L and the correlation dimension D of the running-in attractor is studied.

Findings

In the wear process, the equivalent means chord length L first decreases, then remains steady, and finally increases, this process agrees with the increase, stabilization and decrease of the correlation dimension D. Therefore, the wear particle group has a dynamic nature, which characterizes the formation, stabilization, and disappearance of a running-in attractor. Consequently, the dynamic characteristics and evolution of a running-in attractor can be revealed by the wear particle group.

Originality/value

The intrinsic relationship between the wear particle group and the running-in attractor is proved, and this is advantageous for further revealing the dynamic features of the running-in attractor and identifying the wear states.

Details

Industrial Lubrication and Tribology, vol. 72 no. 5
Type: Research Article
ISSN: 0036-8792

Keywords

Access Restricted. View access options
Article
Publication date: 20 October 2021

Yingwei Liu, Zhe Wang, Chuang Liu and Jingming Ma

This study aims to reveal the differential concentration corrosion (DCC) mechanism, which has been ignored by researchers for a long time.

55

Abstract

Purpose

This study aims to reveal the differential concentration corrosion (DCC) mechanism, which has been ignored by researchers for a long time.

Design/methodology/approach

The ionic conductive layer near the pipe wall was extracted and discretized. In the case of DCC, the equations of corrosion potential after polarization in units are derived according to Kirchhoff’s Law. By solving these equations, the corrosion potential and current on situation of DCC are calculated.

Findings

DCC can change origin distribution of (nature) potential and current greatly; it will cause polarization. The positions with original lower corrosion potential will produce anodic polarization; meanwhile, the speed of corrosion also increases; the position with original higher corrosion potential will produce cathodic polarization, and the corrosion current is also decreased. Generally speaking, the potential will be homogenized by DCC mechanism.

Originality/value

This model makes an in-depth analysis of the traditional FAC theory, greatly supplements it and enriches the theory.

Details

Anti-Corrosion Methods and Materials, vol. 68 no. 6
Type: Research Article
ISSN: 0003-5599

Keywords

1 – 3 of 3
Per page
102050