热扩散不稳定氢/空气火焰的火焰壁相互作用,第二部分:等效比、温度和压力的参数变化

IF 5.8 2区 工程技术 Q2 ENERGY & FUELS
Max Schneider, Hendrik Nicolai, Vinzenz Schuh, Matthias Steinhausen, Christian Hasse
{"title":"热扩散不稳定氢/空气火焰的火焰壁相互作用,第二部分:等效比、温度和压力的参数变化","authors":"Max Schneider,&nbsp;Hendrik Nicolai,&nbsp;Vinzenz Schuh,&nbsp;Matthias Steinhausen,&nbsp;Christian Hasse","doi":"10.1016/j.combustflame.2025.114319","DOIUrl":null,"url":null,"abstract":"<div><div>Fuel-lean hydrogen combustion systems hold significant potential for low pollutant emissions, but are also susceptible to intrinsic flame instabilities. While most research on these instabilities has focused on flames without wall confinement, practical combustors are typically enclosed by walls that strongly influence the combustion dynamics. In part I of this work (Schneider et al., Combust. Flame, 2025), the flame-wall interaction of intrinsically unstable hydrogen/air flames has been studied for a single operating condition through detailed numerical simulations in a two-dimensional head-on quenching configuration. This study builds upon the previous investigation by examining a wide range of gas turbine and engine-relevant operating conditions, including variations in equivalence ratio (0.4–1.0), unburnt gas temperature (<span><math><mrow><mtext>298</mtext><mspace></mspace><mtext>K</mtext></mrow></math></span>–<span><math><mrow><mtext>700</mtext><mspace></mspace><mtext>K</mtext></mrow></math></span>), and pressure (<span><math><mrow><mtext>1.013 25</mtext><mspace></mspace><mtext>bar</mtext></mrow></math></span>–<span><math><mrow><mtext>20</mtext><mspace></mspace><mtext>bar</mtext></mrow></math></span>). These parametric variations allow for a detailed analysis and establish a baseline for modeling the effects of varying instability intensities on the quenching process, as the intensity of thermodiffusive and hydrodynamic instabilities depends on the operating conditions. While the quenching characteristics remain largely unaffected by hydrodynamic instabilities, the presence of thermodiffusive instabilities significantly increases the mean wall-heat flux and reduces the mean quenching distance. Furthermore, the impact of thermodiffusive instabilities on the quenching process intensifies as their intensity increases, driven by an increase in pressures and a decrease in equivalence ratio and unburnt gas temperature. The corresponding relative increase in wall heat flux, compared to a one-dimensional inherently stable head-on quenching flame under identical operating conditions, strongly correlates with the enhanced local reactivity associated with the thermodiffusive instability across all operating conditions. Finally, a joint model fit is proposed to estimate the relative increase in wall heat flux due to intrinsic flame instabilities based on characteristic quantities of a corresponding stable one-dimensional freely-propagating flame.</div><div><strong>Novelty and Significance Statement</strong></div><div>This work presents a novel parametric study of flame-wall interactions (head-on quenching) of intrinsically unstable hydrogen/air flames. It builds upon an investigation of an unstable head-on quenching hydrogen/air flame (part I (Schneider et al., Combust. Flame, 2025)) and extends it to a wide range of operation conditions, including variations in equivalence ratio, unburnt gas temperature, and pressure. Additionally, simulations in which either the thermodiffusive or the hydrodynamic instability is selectively suppressed are conducted to enable a separate analysis of each effect. Based on this comprehensive dataset, the study demonstrates the influence of both thermodiffusive and hydrodynamic instabilities on the quenching process by analyzing the local wall heat flux as well as global quenching characteristics. Furthermore, the study reveals that the intensity of thermodiffusive instabilities correlates well with the increase in the peak wall heat flux relative to a one-dimensional simulation for all operating conditions investigated. To enable the assessment of thermal loads in technical applications, a novel model fit is proposed that allows to estimate the peak wall heat flux during quenching based on characteristic quantities of one-dimensional flames.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"279 ","pages":"Article 114319"},"PeriodicalIF":5.8000,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Flame-wall interaction of thermodiffusively unstable hydrogen/air flames, Part II: Parametric variations of equivalence ratio, temperature, and pressure\",\"authors\":\"Max Schneider,&nbsp;Hendrik Nicolai,&nbsp;Vinzenz Schuh,&nbsp;Matthias Steinhausen,&nbsp;Christian Hasse\",\"doi\":\"10.1016/j.combustflame.2025.114319\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Fuel-lean hydrogen combustion systems hold significant potential for low pollutant emissions, but are also susceptible to intrinsic flame instabilities. While most research on these instabilities has focused on flames without wall confinement, practical combustors are typically enclosed by walls that strongly influence the combustion dynamics. In part I of this work (Schneider et al., Combust. Flame, 2025), the flame-wall interaction of intrinsically unstable hydrogen/air flames has been studied for a single operating condition through detailed numerical simulations in a two-dimensional head-on quenching configuration. This study builds upon the previous investigation by examining a wide range of gas turbine and engine-relevant operating conditions, including variations in equivalence ratio (0.4–1.0), unburnt gas temperature (<span><math><mrow><mtext>298</mtext><mspace></mspace><mtext>K</mtext></mrow></math></span>–<span><math><mrow><mtext>700</mtext><mspace></mspace><mtext>K</mtext></mrow></math></span>), and pressure (<span><math><mrow><mtext>1.013 25</mtext><mspace></mspace><mtext>bar</mtext></mrow></math></span>–<span><math><mrow><mtext>20</mtext><mspace></mspace><mtext>bar</mtext></mrow></math></span>). These parametric variations allow for a detailed analysis and establish a baseline for modeling the effects of varying instability intensities on the quenching process, as the intensity of thermodiffusive and hydrodynamic instabilities depends on the operating conditions. While the quenching characteristics remain largely unaffected by hydrodynamic instabilities, the presence of thermodiffusive instabilities significantly increases the mean wall-heat flux and reduces the mean quenching distance. Furthermore, the impact of thermodiffusive instabilities on the quenching process intensifies as their intensity increases, driven by an increase in pressures and a decrease in equivalence ratio and unburnt gas temperature. The corresponding relative increase in wall heat flux, compared to a one-dimensional inherently stable head-on quenching flame under identical operating conditions, strongly correlates with the enhanced local reactivity associated with the thermodiffusive instability across all operating conditions. Finally, a joint model fit is proposed to estimate the relative increase in wall heat flux due to intrinsic flame instabilities based on characteristic quantities of a corresponding stable one-dimensional freely-propagating flame.</div><div><strong>Novelty and Significance Statement</strong></div><div>This work presents a novel parametric study of flame-wall interactions (head-on quenching) of intrinsically unstable hydrogen/air flames. It builds upon an investigation of an unstable head-on quenching hydrogen/air flame (part I (Schneider et al., Combust. Flame, 2025)) and extends it to a wide range of operation conditions, including variations in equivalence ratio, unburnt gas temperature, and pressure. Additionally, simulations in which either the thermodiffusive or the hydrodynamic instability is selectively suppressed are conducted to enable a separate analysis of each effect. Based on this comprehensive dataset, the study demonstrates the influence of both thermodiffusive and hydrodynamic instabilities on the quenching process by analyzing the local wall heat flux as well as global quenching characteristics. Furthermore, the study reveals that the intensity of thermodiffusive instabilities correlates well with the increase in the peak wall heat flux relative to a one-dimensional simulation for all operating conditions investigated. To enable the assessment of thermal loads in technical applications, a novel model fit is proposed that allows to estimate the peak wall heat flux during quenching based on characteristic quantities of one-dimensional flames.</div></div>\",\"PeriodicalId\":280,\"journal\":{\"name\":\"Combustion and Flame\",\"volume\":\"279 \",\"pages\":\"Article 114319\"},\"PeriodicalIF\":5.8000,\"publicationDate\":\"2025-07-10\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Combustion and Flame\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0010218025003578\",\"RegionNum\":2,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"ENERGY & FUELS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Combustion and Flame","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0010218025003578","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENERGY & FUELS","Score":null,"Total":0}
引用次数: 0

摘要

燃料清洁氢燃烧系统在低污染物排放方面具有显著的潜力,但也容易受到固有火焰不稳定性的影响。虽然对这些不稳定性的大多数研究都集中在没有壁面约束的火焰上,但实际的燃烧室通常被壁面包围,这对燃烧动力学有很大的影响。在这项工作的第一部分(施耐德等人,燃烧。火焰,2025),本质不稳定的氢/空气火焰的火焰-壁相互作用研究了单一操作条件下,通过详细的数值模拟在二维正面淬火配置。本研究以之前的研究为基础,研究了大量燃气轮机和发动机相关的工作条件,包括等效比(0.4-1.0)、未燃烧气体温度(298K-700K)和压力(1.013 25bar-20bar)的变化。由于热扩散和流体动力不稳定性的强度取决于操作条件,这些参数变化允许进行详细分析,并建立基线,以模拟不同不稳定性强度对淬火过程的影响。虽然淬灭特性在很大程度上不受流体动力不稳定性的影响,但热扩散不稳定性的存在显著增加了平均壁面热流密度,减小了平均淬灭距离。此外,热扩散不稳定性对淬火过程的影响随着其强度的增加而增强,这是由压力的增加、等效比和未燃烧气体温度的降低所驱动的。在相同的操作条件下,与一维固有稳定的正面淬火火焰相比,相应的壁面热流的相对增加与所有操作条件下与热扩散不稳定性相关的局部反应性增强密切相关。最后,基于一维稳定自由传播火焰的特征量,提出了一种联合模型拟合来估计由于火焰固有不稳定性引起的壁面热流的相对增加。新颖性和意义声明本工作提出了一种关于本质不稳定氢/空气火焰的火焰-壁相互作用(正面淬火)的新参数研究。它建立在一个不稳定的正面淬火氢气/空气火焰的调查(第一部分)(施耐德等人,燃烧。火焰,2025)),并将其扩展到广泛的操作条件,包括当量比,未燃烧气体温度和压力的变化。此外,进行了选择性抑制热扩散或水动力不稳定性的模拟,以便对每种影响进行单独分析。在此基础上,通过分析局部壁面热流密度和全局淬火特性,论证了热扩散不稳定性和流体动力不稳定性对淬火过程的影响。此外,研究表明,热扩散不稳定性的强度与峰值壁热流密度的增加有很好的相关性,相对于所研究的所有操作条件的一维模拟。为了能够评估技术应用中的热负荷,提出了一种新的模型拟合,该模型拟合允许基于一维火焰的特征量估计淬火期间的峰值壁热流密度。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
Flame-wall interaction of thermodiffusively unstable hydrogen/air flames, Part II: Parametric variations of equivalence ratio, temperature, and pressure
Fuel-lean hydrogen combustion systems hold significant potential for low pollutant emissions, but are also susceptible to intrinsic flame instabilities. While most research on these instabilities has focused on flames without wall confinement, practical combustors are typically enclosed by walls that strongly influence the combustion dynamics. In part I of this work (Schneider et al., Combust. Flame, 2025), the flame-wall interaction of intrinsically unstable hydrogen/air flames has been studied for a single operating condition through detailed numerical simulations in a two-dimensional head-on quenching configuration. This study builds upon the previous investigation by examining a wide range of gas turbine and engine-relevant operating conditions, including variations in equivalence ratio (0.4–1.0), unburnt gas temperature (298K700K), and pressure (1.013 25bar20bar). These parametric variations allow for a detailed analysis and establish a baseline for modeling the effects of varying instability intensities on the quenching process, as the intensity of thermodiffusive and hydrodynamic instabilities depends on the operating conditions. While the quenching characteristics remain largely unaffected by hydrodynamic instabilities, the presence of thermodiffusive instabilities significantly increases the mean wall-heat flux and reduces the mean quenching distance. Furthermore, the impact of thermodiffusive instabilities on the quenching process intensifies as their intensity increases, driven by an increase in pressures and a decrease in equivalence ratio and unburnt gas temperature. The corresponding relative increase in wall heat flux, compared to a one-dimensional inherently stable head-on quenching flame under identical operating conditions, strongly correlates with the enhanced local reactivity associated with the thermodiffusive instability across all operating conditions. Finally, a joint model fit is proposed to estimate the relative increase in wall heat flux due to intrinsic flame instabilities based on characteristic quantities of a corresponding stable one-dimensional freely-propagating flame.
Novelty and Significance Statement
This work presents a novel parametric study of flame-wall interactions (head-on quenching) of intrinsically unstable hydrogen/air flames. It builds upon an investigation of an unstable head-on quenching hydrogen/air flame (part I (Schneider et al., Combust. Flame, 2025)) and extends it to a wide range of operation conditions, including variations in equivalence ratio, unburnt gas temperature, and pressure. Additionally, simulations in which either the thermodiffusive or the hydrodynamic instability is selectively suppressed are conducted to enable a separate analysis of each effect. Based on this comprehensive dataset, the study demonstrates the influence of both thermodiffusive and hydrodynamic instabilities on the quenching process by analyzing the local wall heat flux as well as global quenching characteristics. Furthermore, the study reveals that the intensity of thermodiffusive instabilities correlates well with the increase in the peak wall heat flux relative to a one-dimensional simulation for all operating conditions investigated. To enable the assessment of thermal loads in technical applications, a novel model fit is proposed that allows to estimate the peak wall heat flux during quenching based on characteristic quantities of one-dimensional flames.
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
Combustion and Flame
Combustion and Flame 工程技术-工程:化工
CiteScore
9.50
自引率
20.50%
发文量
631
审稿时长
3.8 months
期刊介绍: The mission of the journal is to publish high quality work from experimental, theoretical, and computational investigations on the fundamentals of combustion phenomena and closely allied matters. While submissions in all pertinent areas are welcomed, past and recent focus of the journal has been on: Development and validation of reaction kinetics, reduction of reaction mechanisms and modeling of combustion systems, including: Conventional, alternative and surrogate fuels; Pollutants; Particulate and aerosol formation and abatement; Heterogeneous processes. Experimental, theoretical, and computational studies of laminar and turbulent combustion phenomena, including: Premixed and non-premixed flames; Ignition and extinction phenomena; Flame propagation; Flame structure; Instabilities and swirl; Flame spread; Multi-phase reactants. Advances in diagnostic and computational methods in combustion, including: Measurement and simulation of scalar and vector properties; Novel techniques; State-of-the art applications. Fundamental investigations of combustion technologies and systems, including: Internal combustion engines; Gas turbines; Small- and large-scale stationary combustion and power generation; Catalytic combustion; Combustion synthesis; Combustion under extreme conditions; New concepts.
×
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
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
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 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:604180095
Book学术官方微信