偏移射流宽度对双射流中周期性流动的影响

IF 2.5 3区 工程技术 Q2 MECHANICS European Journal of Mechanics B-fluids Pub Date : 2024-10-20 DOI:10.1016/j.euromechflu.2024.10.005
Tanmoy Mondal
{"title":"偏移射流宽度对双射流中周期性流动的影响","authors":"Tanmoy Mondal","doi":"10.1016/j.euromechflu.2024.10.005","DOIUrl":null,"url":null,"abstract":"<div><div>The primary aim of this work is to investigate the impact of the offset jet width on the unsteady flow characteristics of a turbulent dual jet, which consists of a wall jet and an offset jet. A computational fluid dynamics code is developed to solve the unsteady Reynolds-averaged Navier–Stokes (URANS) equations. The width of the offset jet is varied while keeping the width of the wall jet constant at the separation distance between the two jets. When the ratio of the offset jet width (<span><math><mi>w</mi></math></span>) to the separation distance (<span><math><mi>d</mi></math></span>) is <span><math><mrow><mi>w</mi><mo>/</mo><mi>d</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>5</mn></mrow></math></span>, the flow field exhibits a periodic vortex shedding phenomenon. Conversely, when <span><math><mrow><mi>w</mi><mo>/</mo><mi>d</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>4</mn></mrow></math></span>, the flow field remains steady. The shedding phenomenon is discernible even when <span><math><mrow><mi>w</mi><mo>/</mo><mi>d</mi><mo>=</mo><mn>2</mn></mrow></math></span>. The instantaneous velocity components display sinusoidal oscillations at <span><math><mrow><mn>0</mn><mo>.</mo><mn>5</mn><mo>≤</mo><mi>w</mi><mo>/</mo><mi>d</mi><mo>≤</mo><mn>2</mn></mrow></math></span>. Applying the fast Fourier transform to these sinusoidal signals yields a distinct frequency peak at the vortex shedding frequency. Within the range of <span><math><mrow><mn>0</mn><mo>.</mo><mn>5</mn><mo>≤</mo><mi>w</mi><mo>/</mo><mi>d</mi><mo>≤</mo><mn>2</mn></mrow></math></span>, the shedding frequency decreases as the width of the offset jet increases. This trend continues until it reaches a constant value at <span><math><mrow><mi>w</mi><mo>/</mo><mi>d</mi><mo>=</mo><mn>1</mn><mo>.</mo><mn>4</mn></mrow></math></span>. This indicates that the width of the offset jet has a notable influence on the shedding phenomenon within the range of <span><math><mrow><mn>0</mn><mo>.</mo><mn>5</mn><mo>≤</mo><mi>w</mi><mo>/</mo><mi>d</mi><mo>≤</mo><mn>1</mn><mo>.</mo><mn>4</mn></mrow></math></span>. For <span><math><mrow><mn>1</mn><mo>.</mo><mn>4</mn><mo>&lt;</mo><mi>w</mi><mo>/</mo><mi>d</mi><mo>≤</mo><mn>2</mn></mrow></math></span>, the shedding frequency remains unaffected by the offset jet width variation. Depending on the value of <span><math><mrow><mi>w</mi><mo>/</mo><mi>d</mi></mrow></math></span>, the shedding phenomenon is characterized by three flow regimes: a steady flow regime (for<span><math><mrow><mi>w</mi><mo>/</mo><mi>d</mi><mo>≤</mo><mn>0</mn><mo>.</mo><mn>4</mn></mrow></math></span>), an outer share layer-influenced shedding regime (for <span><math><mrow><mi>w</mi><mo>/</mo><mi>d</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>5</mn><mo>−</mo><mn>1</mn><mo>.</mo><mn>4</mn></mrow></math></span>), and an outer shear layer-free shedding regime (for <span><math><mrow><mi>w</mi><mo>/</mo><mi>d</mi><mo>&gt;</mo><mn>1</mn><mo>.</mo><mn>4</mn></mrow></math></span>).</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"109 ","pages":"Pages 253-270"},"PeriodicalIF":2.5000,"publicationDate":"2024-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Effects of offset jet width on periodic flow in a dual jet\",\"authors\":\"Tanmoy Mondal\",\"doi\":\"10.1016/j.euromechflu.2024.10.005\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>The primary aim of this work is to investigate the impact of the offset jet width on the unsteady flow characteristics of a turbulent dual jet, which consists of a wall jet and an offset jet. A computational fluid dynamics code is developed to solve the unsteady Reynolds-averaged Navier–Stokes (URANS) equations. The width of the offset jet is varied while keeping the width of the wall jet constant at the separation distance between the two jets. When the ratio of the offset jet width (<span><math><mi>w</mi></math></span>) to the separation distance (<span><math><mi>d</mi></math></span>) is <span><math><mrow><mi>w</mi><mo>/</mo><mi>d</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>5</mn></mrow></math></span>, the flow field exhibits a periodic vortex shedding phenomenon. Conversely, when <span><math><mrow><mi>w</mi><mo>/</mo><mi>d</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>4</mn></mrow></math></span>, the flow field remains steady. The shedding phenomenon is discernible even when <span><math><mrow><mi>w</mi><mo>/</mo><mi>d</mi><mo>=</mo><mn>2</mn></mrow></math></span>. The instantaneous velocity components display sinusoidal oscillations at <span><math><mrow><mn>0</mn><mo>.</mo><mn>5</mn><mo>≤</mo><mi>w</mi><mo>/</mo><mi>d</mi><mo>≤</mo><mn>2</mn></mrow></math></span>. Applying the fast Fourier transform to these sinusoidal signals yields a distinct frequency peak at the vortex shedding frequency. Within the range of <span><math><mrow><mn>0</mn><mo>.</mo><mn>5</mn><mo>≤</mo><mi>w</mi><mo>/</mo><mi>d</mi><mo>≤</mo><mn>2</mn></mrow></math></span>, the shedding frequency decreases as the width of the offset jet increases. This trend continues until it reaches a constant value at <span><math><mrow><mi>w</mi><mo>/</mo><mi>d</mi><mo>=</mo><mn>1</mn><mo>.</mo><mn>4</mn></mrow></math></span>. This indicates that the width of the offset jet has a notable influence on the shedding phenomenon within the range of <span><math><mrow><mn>0</mn><mo>.</mo><mn>5</mn><mo>≤</mo><mi>w</mi><mo>/</mo><mi>d</mi><mo>≤</mo><mn>1</mn><mo>.</mo><mn>4</mn></mrow></math></span>. For <span><math><mrow><mn>1</mn><mo>.</mo><mn>4</mn><mo>&lt;</mo><mi>w</mi><mo>/</mo><mi>d</mi><mo>≤</mo><mn>2</mn></mrow></math></span>, the shedding frequency remains unaffected by the offset jet width variation. Depending on the value of <span><math><mrow><mi>w</mi><mo>/</mo><mi>d</mi></mrow></math></span>, the shedding phenomenon is characterized by three flow regimes: a steady flow regime (for<span><math><mrow><mi>w</mi><mo>/</mo><mi>d</mi><mo>≤</mo><mn>0</mn><mo>.</mo><mn>4</mn></mrow></math></span>), an outer share layer-influenced shedding regime (for <span><math><mrow><mi>w</mi><mo>/</mo><mi>d</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>5</mn><mo>−</mo><mn>1</mn><mo>.</mo><mn>4</mn></mrow></math></span>), and an outer shear layer-free shedding regime (for <span><math><mrow><mi>w</mi><mo>/</mo><mi>d</mi><mo>&gt;</mo><mn>1</mn><mo>.</mo><mn>4</mn></mrow></math></span>).</div></div>\",\"PeriodicalId\":11985,\"journal\":{\"name\":\"European Journal of Mechanics B-fluids\",\"volume\":\"109 \",\"pages\":\"Pages 253-270\"},\"PeriodicalIF\":2.5000,\"publicationDate\":\"2024-10-20\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"European Journal of Mechanics B-fluids\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0997754624001432\",\"RegionNum\":3,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"MECHANICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"European Journal of Mechanics B-fluids","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0997754624001432","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MECHANICS","Score":null,"Total":0}
引用次数: 0

摘要

这项工作的主要目的是研究偏置射流宽度对湍流双射流(由壁面射流和偏置射流组成)非稳态流动特性的影响。开发了一种计算流体动力学代码,用于求解雷诺平均纳维-斯托克斯(URANS)非稳态方程。偏置射流的宽度是变化的,而壁面射流的宽度在两个射流的分离距离上保持不变。当偏置射流宽度(w)与分离距离(d)之比为 w/d=0.5 时,流场呈现周期性涡流脱落现象。相反,当 w/d=0.4 时,流场保持稳定。即使当 w/d=2 时,也能看到脱落现象。瞬时速度分量在 0.5≤w/d≤2 时显示正弦振荡。对这些正弦信号进行快速傅里叶变换后,会在涡流脱落频率处产生一个明显的频率峰。在 0.5≤w/d≤2 的范围内,脱落频率随着偏移射流宽度的增加而降低。这一趋势一直持续到 w/d=1.4 时达到恒定值。这表明在 0.5≤w/d≤1.4 的范围内,偏置射流的宽度对脱落现象有显著影响。对于 1.4<w/d≤2,脱落频率不受偏置射流宽度变化的影响。根据 w/d 值的不同,脱落现象有三种流态:稳定流态(w/d≤0.4 时)、受外共享层影响的脱落态(w/d=0.5-1.4 时)和无外剪切层的脱落态(w/d>1.4 时)。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
查看原文
分享 分享
微信好友 朋友圈 QQ好友 复制链接
本刊更多论文
Effects of offset jet width on periodic flow in a dual jet
The primary aim of this work is to investigate the impact of the offset jet width on the unsteady flow characteristics of a turbulent dual jet, which consists of a wall jet and an offset jet. A computational fluid dynamics code is developed to solve the unsteady Reynolds-averaged Navier–Stokes (URANS) equations. The width of the offset jet is varied while keeping the width of the wall jet constant at the separation distance between the two jets. When the ratio of the offset jet width (w) to the separation distance (d) is w/d=0.5, the flow field exhibits a periodic vortex shedding phenomenon. Conversely, when w/d=0.4, the flow field remains steady. The shedding phenomenon is discernible even when w/d=2. The instantaneous velocity components display sinusoidal oscillations at 0.5w/d2. Applying the fast Fourier transform to these sinusoidal signals yields a distinct frequency peak at the vortex shedding frequency. Within the range of 0.5w/d2, the shedding frequency decreases as the width of the offset jet increases. This trend continues until it reaches a constant value at w/d=1.4. This indicates that the width of the offset jet has a notable influence on the shedding phenomenon within the range of 0.5w/d1.4. For 1.4<w/d2, the shedding frequency remains unaffected by the offset jet width variation. Depending on the value of w/d, the shedding phenomenon is characterized by three flow regimes: a steady flow regime (forw/d0.4), an outer share layer-influenced shedding regime (for w/d=0.51.4), and an outer shear layer-free shedding regime (for w/d>1.4).
求助全文
通过发布文献求助,成功后即可免费获取论文全文。 去求助
来源期刊
CiteScore
5.90
自引率
3.80%
发文量
127
审稿时长
58 days
期刊介绍: The European Journal of Mechanics - B/Fluids publishes papers in all fields of fluid mechanics. Although investigations in well-established areas are within the scope of the journal, recent developments and innovative ideas are particularly welcome. Theoretical, computational and experimental papers are equally welcome. Mathematical methods, be they deterministic or stochastic, analytical or numerical, will be accepted provided they serve to clarify some identifiable problems in fluid mechanics, and provided the significance of results is explained. Similarly, experimental papers must add physical insight in to the understanding of fluid mechanics.
期刊最新文献
Influence of structural parameters on the performance of fluid oscillators Prediction of wind loading on masked angle members in lattice tower structures Turbulent spiral flow of power-law fluid in annular channel Study of the motion and interaction of micro-swimmers with different scales in Poiseuille flow Vertical concentration distribution of fine settling particles in a pulsatile laminar open channel flow
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
已复制链接
已复制链接
快去分享给好友吧!
我知道了
×
扫码分享
扫码分享
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1