Effect of Pipe Wall Wear Defects on the Flow Characteristics of Slurry Shield Discharge Pipe

During slurry shield tunneling in hard rock or cobble strata, the discharge pipes suffer serve wear and damage. However, the effect mechanism of pipe wall wear defects on the flow characteristics of two-phase flow is unclear. In this study, a three-dimensional slurry particle model of pipeline trans...

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Main Authors: Yingran Fang, Xinggao Li, Xingchun Li, Yidong Guo, Hongzhi Liu
Format: Article
Language:English
Published: MDPI AG 2025-02-01
Series:Lubricants
Subjects:
Online Access:https://www.mdpi.com/2075-4442/13/2/68
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author Yingran Fang
Xinggao Li
Xingchun Li
Yidong Guo
Hongzhi Liu
author_facet Yingran Fang
Xinggao Li
Xingchun Li
Yidong Guo
Hongzhi Liu
author_sort Yingran Fang
collection DOAJ
description During slurry shield tunneling in hard rock or cobble strata, the discharge pipes suffer serve wear and damage. However, the effect mechanism of pipe wall wear defects on the flow characteristics of two-phase flow is unclear. In this study, a three-dimensional slurry particle model of pipeline transport was established using the coupled computational fluid dynamics–discrete element method (CFD-DEM) considering the pipe wall wear defect, and the typical pipeline forms of straight pipe and 90° elbow pipe were selected as the research targets. The results indicated that the localized wear defect of pipes can lead to increased inhomogeneity in the velocity distribution, generating localized low-flow zones and resulting in a reduced flow rate or stagnancy in parts of the pipe. Meanwhile, the wear defect of the pipe results in local shape changes, so that the fluid flow path through the pipe is no longer smooth, causing more vortex/turbulence and secondary flow, where an increased vortex promotes localized kinetic energy reduction and creates larger pressure losses at the elbow. In addition, for the elbow pipe without wear defect, the pressure drop of the elbow increases quadratically from an increase of 6.5% to an increase of 16.9%, with the maximum wear depth increasing from 4 mm to 19 mm. For the straight pipe without wear defect, the pressure drop of the elbow increases linearly, from an increase of 2.2% to an increase of 10.2% with the maximum wear depth increasing from 4 mm to 19 mm. The paper investigates the potential mechanism of pipe flow characteristics influenced by wear defect and provides practical guidelines for the efficient operation of a slurry shield circulating system.
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id doaj-art-3d54253dc83949f7942a914815e75b39
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issn 2075-4442
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series Lubricants
spelling doaj-art-3d54253dc83949f7942a914815e75b392025-08-20T02:44:39ZengMDPI AGLubricants2075-44422025-02-011326810.3390/lubricants13020068Effect of Pipe Wall Wear Defects on the Flow Characteristics of Slurry Shield Discharge PipeYingran Fang0Xinggao Li1Xingchun Li2Yidong Guo3Hongzhi Liu4Key Laboratory of Urban Underground Engineering of the Education Ministry, Beijing Jiaotong University, Beijing 100044, ChinaKey Laboratory of Urban Underground Engineering of the Education Ministry, Beijing Jiaotong University, Beijing 100044, ChinaSchool of Electronics and Information Engineering, Wuyi University, Jiangmen 529020, ChinaKey Laboratory of Urban Underground Engineering of the Education Ministry, Beijing Jiaotong University, Beijing 100044, ChinaCCCC Tunnel Engineering Co., Ltd., Beijing 100024, ChinaDuring slurry shield tunneling in hard rock or cobble strata, the discharge pipes suffer serve wear and damage. However, the effect mechanism of pipe wall wear defects on the flow characteristics of two-phase flow is unclear. In this study, a three-dimensional slurry particle model of pipeline transport was established using the coupled computational fluid dynamics–discrete element method (CFD-DEM) considering the pipe wall wear defect, and the typical pipeline forms of straight pipe and 90° elbow pipe were selected as the research targets. The results indicated that the localized wear defect of pipes can lead to increased inhomogeneity in the velocity distribution, generating localized low-flow zones and resulting in a reduced flow rate or stagnancy in parts of the pipe. Meanwhile, the wear defect of the pipe results in local shape changes, so that the fluid flow path through the pipe is no longer smooth, causing more vortex/turbulence and secondary flow, where an increased vortex promotes localized kinetic energy reduction and creates larger pressure losses at the elbow. In addition, for the elbow pipe without wear defect, the pressure drop of the elbow increases quadratically from an increase of 6.5% to an increase of 16.9%, with the maximum wear depth increasing from 4 mm to 19 mm. For the straight pipe without wear defect, the pressure drop of the elbow increases linearly, from an increase of 2.2% to an increase of 10.2% with the maximum wear depth increasing from 4 mm to 19 mm. The paper investigates the potential mechanism of pipe flow characteristics influenced by wear defect and provides practical guidelines for the efficient operation of a slurry shield circulating system.https://www.mdpi.com/2075-4442/13/2/68slurry shielddischarge pipewear defect of pipe wallflow characteristicsCFD-DEM-coupled modeling
spellingShingle Yingran Fang
Xinggao Li
Xingchun Li
Yidong Guo
Hongzhi Liu
Effect of Pipe Wall Wear Defects on the Flow Characteristics of Slurry Shield Discharge Pipe
Lubricants
slurry shield
discharge pipe
wear defect of pipe wall
flow characteristics
CFD-DEM-coupled modeling
title Effect of Pipe Wall Wear Defects on the Flow Characteristics of Slurry Shield Discharge Pipe
title_full Effect of Pipe Wall Wear Defects on the Flow Characteristics of Slurry Shield Discharge Pipe
title_fullStr Effect of Pipe Wall Wear Defects on the Flow Characteristics of Slurry Shield Discharge Pipe
title_full_unstemmed Effect of Pipe Wall Wear Defects on the Flow Characteristics of Slurry Shield Discharge Pipe
title_short Effect of Pipe Wall Wear Defects on the Flow Characteristics of Slurry Shield Discharge Pipe
title_sort effect of pipe wall wear defects on the flow characteristics of slurry shield discharge pipe
topic slurry shield
discharge pipe
wear defect of pipe wall
flow characteristics
CFD-DEM-coupled modeling
url https://www.mdpi.com/2075-4442/13/2/68
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AT xingchunli effectofpipewallweardefectsontheflowcharacteristicsofslurryshielddischargepipe
AT yidongguo effectofpipewallweardefectsontheflowcharacteristicsofslurryshielddischargepipe
AT hongzhiliu effectofpipewallweardefectsontheflowcharacteristicsofslurryshielddischargepipe