{"title":"A Thickened flame model extension for the simulation of lean hydrogen-air explosions in confined environments","authors":"Jean-Jacques Hok, Omar Dounia, Olivier Vermorel","doi":"10.1016/j.combustflame.2025.114070","DOIUrl":null,"url":null,"abstract":"<div><div>This paper investigates the coupling between wall confinement and flame front instabilities during lean H<sub>2</sub>-air deflagrations in tubes. Flame-Resolved Simulations (FRS) show that confinement significantly affects flame behavior: (1) in narrow tubes, confinement effects dominate over flame instabilities and flame acceleration is driven dominantly by the finger flame mechanism, (2) while in wider tubes, instabilities have more space to develop, thereby enhancing their contribution to flame acceleration. In a large-scale modeling perspective, the paper delves into ways to reproduce the complex interaction between confinement and flame front instabilities using coarser meshes. Strong limitations of the Thickened Flame (TF) model, a classical approach for the Large Eddy Simulations (LES) for reactive flows, are first highlighted. The inherent inability of the TF approach to reproduce the specificities of lean H<sub>2</sub>-air combustion is solved by employing the Thermo-Diffusive-Stretched-Thickened Flame (TD-S-TF) model initially developed in Hok et al. (2024) and extending it to account for confinement effects: the model incorporates a time-dependent efficiency function mimicking the effects of subgrid thermo-diffusive instabilities on flame acceleration, and saturated to account for the limited instability growth in confined spaces. Although such saturation is only demonstrated for the simple tube configuration, this strategy solves issues encountered with the TF model, thereby paving the way for accurate confined H<sub>2</sub>-air explosions simulations.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"275 ","pages":"Article 114070"},"PeriodicalIF":5.8000,"publicationDate":"2025-03-05","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/S0010218025001087","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
Abstract
This paper investigates the coupling between wall confinement and flame front instabilities during lean H2-air deflagrations in tubes. Flame-Resolved Simulations (FRS) show that confinement significantly affects flame behavior: (1) in narrow tubes, confinement effects dominate over flame instabilities and flame acceleration is driven dominantly by the finger flame mechanism, (2) while in wider tubes, instabilities have more space to develop, thereby enhancing their contribution to flame acceleration. In a large-scale modeling perspective, the paper delves into ways to reproduce the complex interaction between confinement and flame front instabilities using coarser meshes. Strong limitations of the Thickened Flame (TF) model, a classical approach for the Large Eddy Simulations (LES) for reactive flows, are first highlighted. The inherent inability of the TF approach to reproduce the specificities of lean H2-air combustion is solved by employing the Thermo-Diffusive-Stretched-Thickened Flame (TD-S-TF) model initially developed in Hok et al. (2024) and extending it to account for confinement effects: the model incorporates a time-dependent efficiency function mimicking the effects of subgrid thermo-diffusive instabilities on flame acceleration, and saturated to account for the limited instability growth in confined spaces. Although such saturation is only demonstrated for the simple tube configuration, this strategy solves issues encountered with the TF model, thereby paving the way for accurate confined H2-air explosions simulations.
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.
京公网安备 11010802042870号
京ICP备2023020795号-1
分享
求助内容：
应助结果提醒方式：
扫码关注我们
