Shuai Huang , Yachao Chang , Ying Huo , Pengzhi Wang , Yuxiang Zhu , Jiaxin Liu , Shangkun Zhou , Jintao Chen , Qingmiao Ding , Henry J. Curran , Ming Jia
{"title":"Updated reaction rate rules for the construction and derivation of skeletal chemical mechanisms of lightly branched isoalkanes","authors":"Shuai Huang , Yachao Chang , Ying Huo , Pengzhi Wang , Yuxiang Zhu , Jiaxin Liu , Shangkun Zhou , Jintao Chen , Qingmiao Ding , Henry J. Curran , Ming Jia","doi":"10.1016/j.combustflame.2025.114340","DOIUrl":null,"url":null,"abstract":"<div><div><em>Iso</em>-alkanes are found in large quantities in both novel and conventional fuels. Accurate kinetic models for these fuels are essential for numerical simulations of combustion engines. However, existing chemical kinetic mechanisms are insufficient to fully elucidate the combustion chemistry of alkane isomers. Additionally, the influence of molecular structure differences between iso-alkanes, specifically differences in the position and number of methyl branches on their low-temperature oxidation pathways has not been comprehensively studied. The relationship between fuel properties, such as auto-ignition behavior and flame characteristics, and molecular structure is still not fully understood. The present study proposes updated reaction rate rules to establish skeletal kinetic mechanisms for monomethyl and dimethyl iso-alkanes with different positions of methyl substitution. Firstly, the important reaction classes from the sub-mechanisms of the hexane isomers are identified using reaction-class-based global sensitivity analysis. Subsequently, skeletal chemical mechanisms for 2-methyl and 3-methyl pentane are constructed, following a comparison of their critical reaction pathways. It is observed that the location of the methyl group significantly influences the positions of the critical H-atom abstraction reactions. This work further extends the study to dimethyl hexane isomers, by considering 2,2- and 2,3-dimethyl butane, and 2,3- and 2,4-dimethyl pentane. By integrating the monomethyl and dimethyl alkanes, reaction rate rules are updated for the construction of skeletal chemical mechanisms for larger iso-alkanes with similar molecular structures. Using reaction rate rules, skeletal chemical mechanisms of monomethyl and dimethyl iso-alkanes up to C<sub>10</sub> are constructed. Comparisons between experimental data and simulations show good agreement, demonstrating the robustness of the monomethyl and dimethyl iso-alkanes chemical mechanisms and the effectiveness of the proposed reaction rate rules.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"279 ","pages":"Article 114340"},"PeriodicalIF":5.8000,"publicationDate":"2025-07-08","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/S0010218025003773","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
Iso-alkanes are found in large quantities in both novel and conventional fuels. Accurate kinetic models for these fuels are essential for numerical simulations of combustion engines. However, existing chemical kinetic mechanisms are insufficient to fully elucidate the combustion chemistry of alkane isomers. Additionally, the influence of molecular structure differences between iso-alkanes, specifically differences in the position and number of methyl branches on their low-temperature oxidation pathways has not been comprehensively studied. The relationship between fuel properties, such as auto-ignition behavior and flame characteristics, and molecular structure is still not fully understood. The present study proposes updated reaction rate rules to establish skeletal kinetic mechanisms for monomethyl and dimethyl iso-alkanes with different positions of methyl substitution. Firstly, the important reaction classes from the sub-mechanisms of the hexane isomers are identified using reaction-class-based global sensitivity analysis. Subsequently, skeletal chemical mechanisms for 2-methyl and 3-methyl pentane are constructed, following a comparison of their critical reaction pathways. It is observed that the location of the methyl group significantly influences the positions of the critical H-atom abstraction reactions. This work further extends the study to dimethyl hexane isomers, by considering 2,2- and 2,3-dimethyl butane, and 2,3- and 2,4-dimethyl pentane. By integrating the monomethyl and dimethyl alkanes, reaction rate rules are updated for the construction of skeletal chemical mechanisms for larger iso-alkanes with similar molecular structures. Using reaction rate rules, skeletal chemical mechanisms of monomethyl and dimethyl iso-alkanes up to C10 are constructed. Comparisons between experimental data and simulations show good agreement, demonstrating the robustness of the monomethyl and dimethyl iso-alkanes chemical mechanisms and the effectiveness of the proposed reaction rate rules.
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.