Chemical kinetic insights into the ignition dynamics of n-hexane

Handle URI:
http://hdl.handle.net/10754/625881
Title:
Chemical kinetic insights into the ignition dynamics of n-hexane
Authors:
Tingas, Alexandros ( 0000-0001-8849-1251 ) ; Wang, Zhandong ( 0000-0003-1535-2319 ) ; Sarathy, Mani ( 0000-0002-3975-6206 ) ; Im, Hong G. ( 0000-0001-7080-1266 ) ; Goussis, Dimitris A.
Abstract:
Normal alkanes constitute a significant fraction of transportation fuels, and are the primary drivers of ignition processes in gasoline and diesel fuels. Low temperature ignition of n-alkanes is driven by a complex sequence of oxidation reactions, for which detailed mechanisms are still being developed. The current study explores the dynamics of low-temperature ignition of n-hexane/air mixtures, and identifies chemical pathways that characterize the combustion process. Two chemical kinetic mechanisms were selected as a comparative study in order to better understand the role of specific reaction sequences in ignition dynamics: one mechanism including a new third sequential O2 addition reaction pathways (recently proposed by Wang et al. 2017), while the other without (Zhang et al. 2015). The analysis is conducted by applying tools generated from the computational singular perturbation (CSP) approach to two distinct ignition phenomena: constant volume and compression ignition. In both cases, the role of the third sequential O2 addition reactions proves to be significant, although it is found to be much more pronounced in the constant volume cases compared to the HCCI. In particular, in the constant volume ignition case, reactions present in the third sequential O2 addition reaction pathways (e.g., KDHP  →  products + OH) contribute significantly to the explosivity of the mixture; when accounted for along with reactions P(OOH)2 + O2  →  OOP(OOH)2 and OOP(OOH)2  →  KDHP + OH, they decrease ignition delay time of the mixture by up to 40%. Under HCCI conditions, in the first-stage ignition, the third-O2 addition reactions contribute to the process, although their role decays with time and becomes negligible at the end of the first stage. The second ignition stage is dominated almost exclusively by hydrogen-related chemistry.
KAUST Department:
Clean Combustion Research Center
Citation:
Tingas E-A, Wang Z, Mani Sarathy S, Im HG, Goussis DA (2018) Chemical kinetic insights into the ignition dynamics of n-hexane. Combustion and Flame 188: 28–40. Available: http://dx.doi.org/10.1016/j.combustflame.2017.09.024.
Publisher:
Elsevier BV
Journal:
Combustion and Flame
Issue Date:
13-Oct-2017
DOI:
10.1016/j.combustflame.2017.09.024
Type:
Article
ISSN:
0010-2180
Sponsors:
This work was sponsored by competitive research funding from King Abdullah University of Science and Technology.
Additional Links:
http://www.sciencedirect.com/science/article/pii/S0010218017303619
Appears in Collections:
Articles; Clean Combustion Research Center

Full metadata record

DC FieldValue Language
dc.contributor.authorTingas, Alexandrosen
dc.contributor.authorWang, Zhandongen
dc.contributor.authorSarathy, Manien
dc.contributor.authorIm, Hong G.en
dc.contributor.authorGoussis, Dimitris A.en
dc.date.accessioned2017-10-17T11:32:08Z-
dc.date.available2017-10-17T11:32:08Z-
dc.date.issued2017-10-13en
dc.identifier.citationTingas E-A, Wang Z, Mani Sarathy S, Im HG, Goussis DA (2018) Chemical kinetic insights into the ignition dynamics of n-hexane. Combustion and Flame 188: 28–40. Available: http://dx.doi.org/10.1016/j.combustflame.2017.09.024.en
dc.identifier.issn0010-2180en
dc.identifier.doi10.1016/j.combustflame.2017.09.024en
dc.identifier.urihttp://hdl.handle.net/10754/625881-
dc.description.abstractNormal alkanes constitute a significant fraction of transportation fuels, and are the primary drivers of ignition processes in gasoline and diesel fuels. Low temperature ignition of n-alkanes is driven by a complex sequence of oxidation reactions, for which detailed mechanisms are still being developed. The current study explores the dynamics of low-temperature ignition of n-hexane/air mixtures, and identifies chemical pathways that characterize the combustion process. Two chemical kinetic mechanisms were selected as a comparative study in order to better understand the role of specific reaction sequences in ignition dynamics: one mechanism including a new third sequential O2 addition reaction pathways (recently proposed by Wang et al. 2017), while the other without (Zhang et al. 2015). The analysis is conducted by applying tools generated from the computational singular perturbation (CSP) approach to two distinct ignition phenomena: constant volume and compression ignition. In both cases, the role of the third sequential O2 addition reactions proves to be significant, although it is found to be much more pronounced in the constant volume cases compared to the HCCI. In particular, in the constant volume ignition case, reactions present in the third sequential O2 addition reaction pathways (e.g., KDHP  →  products + OH) contribute significantly to the explosivity of the mixture; when accounted for along with reactions P(OOH)2 + O2  →  OOP(OOH)2 and OOP(OOH)2  →  KDHP + OH, they decrease ignition delay time of the mixture by up to 40%. Under HCCI conditions, in the first-stage ignition, the third-O2 addition reactions contribute to the process, although their role decays with time and becomes negligible at the end of the first stage. The second ignition stage is dominated almost exclusively by hydrogen-related chemistry.en
dc.description.sponsorshipThis work was sponsored by competitive research funding from King Abdullah University of Science and Technology.en
dc.publisherElsevier BVen
dc.relation.urlhttp://www.sciencedirect.com/science/article/pii/S0010218017303619en
dc.rightsNOTICE: this is the author’s version of a work that was accepted for publication in Combustion and Flame. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Combustion and Flame, 10 October 2017. DOI: 10.1016/j.combustflame.2017.09.024. © 2017. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/en
dc.subjectCSPen
dc.subjectExplosive dynamicsen
dc.subjectn-hexaneen
dc.subjectThird sequential O2 addition reactionsen
dc.subjectAutoignitionen
dc.subjectLow-temperature oxidationen
dc.titleChemical kinetic insights into the ignition dynamics of n-hexaneen
dc.typeArticleen
dc.contributor.departmentClean Combustion Research Centeren
dc.identifier.journalCombustion and Flameen
dc.eprint.versionPost-printen
dc.contributor.institutionDepartment of Mechanical Engineering, Khalifa University of Science, Technology and Research (KUSTAR), Abu Dhabi 127788, United Arab Emiratesen
dc.contributor.institutionDepartment of Mechanics, School of Applied Mathematical and Physical Sciences, National Technical University of Athens (NTUA), Athens 15780, Greeceen
kaust.authorTingas, Alexandrosen
kaust.authorWang, Zhandongen
kaust.authorSarathy, Manien
kaust.authorIm, Hong G.en
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