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dc.contributor.authorYu, Gwang Hyeon
dc.contributor.authorLuong, Minh Bau
dc.contributor.authorChung, Suk Ho
dc.contributor.authorYoo, Chun Sang
dc.date.accessioned2019-08-08T07:01:31Z
dc.date.available2019-08-08T07:01:31Z
dc.date.issued2019-07-16
dc.identifier.citationYu, G. H., Luong, M. B., Chung, S. H., & Yoo, C. S. (2019). Ignition characteristics of a temporally evolving n-heptane jet in an iso-octane/air stream under RCCI combustion-relevant conditions. Combustion and Flame, 208, 299–312. doi:10.1016/j.combustflame.2019.07.011
dc.identifier.doi10.1016/j.combustflame.2019.07.011
dc.identifier.urihttp://hdl.handle.net/10754/656420
dc.description.abstractThe ignition characteristics of a temporally-evolving n-heptane jet in an iso-octane/air stream under reactivity controlled compression ignition (RCCI) combustion-relevant conditions are investigated using 2-D direct numerical simulations (DNSs) with a 116-species primary reference fuel (PRF)/air reduced mechanism. For the DNSs of RCCI combustion, iso-octane and n-heptane are chosen as two different fuels delivered by the port-fuel and direct-fuel injections, respectively. Therefore, the ignition characteristics of both fuels can be investigated by simulating the ignition of a temporally-evolving n-heptane jet with relative jet velocity, U0, within iso-octane/air charge. It is found that the first-stage ignition kernels governed by the low-temperature chemistry first develop primarily within the n-heptane jet near the mixing layer regardless of U0, and evolve into low-temperature flames, propagating into relatively fuel-rich mixtures in the n-heptane jet. High-temperature flames also develop first in the n-heptane jet, following the trajectories of low-temperature flames, and then, propagate towards both relatively fuel-lean mixtures of the iso-octane/air charge and fuel-rich mixtures of the n-heptane jet. They keep propagating into fuel-lean mixtures and finally end-gas auto-ignition occurs. It is also found that the first-stage ignition occurs more quickly with increasing U0 due to enhanced mixing between relatively cold n-heptane jet and hot iso-octane/air charge, and consequently, the second-stage ignition also advances in time with increasing U0, which are opposite to the results found in previous DNSs of RCCI combustion. Such ignition characteristics are more likely to prolong the overall combustion duration and reduce the peak of heat release rate with increasing U0. In addition, chemical explosive mode analysis (CEMA) identifies important variables and reactions for the low-, intermediate-, and high-temperature chemistries under such RCCI conditions.
dc.description.sponsorshipThis research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (NRF-2018R1A2A2A05018901). This research used the resources of the KAUST Supercomputing Laboratory and the UNIST Supercomputing Center.
dc.publisherElsevier BV
dc.relation.urlhttps://linkinghub.elsevier.com/retrieve/pii/S0010218019303037
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, [[Volume], [Issue], (2019-07-16)] DOI: 10.1016/j.combustflame.2019.07.011 . © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/4.0/
dc.subjectDirect numerical simulation (DNS)
dc.subjectReactivity-controlled compression ignition (RCCI)
dc.subjectPrimary reference fuel (PRF)
dc.subjectMixing layer
dc.subjectChemical explosive mode analysis (CEMA)
dc.titleIgnition characteristics of a temporally evolving n-heptane jet in an iso-octane/air stream under RCCI combustion-relevant conditions
dc.typeArticle
dc.contributor.departmentCombustion and Laser Diagnostics Laboratory
dc.contributor.departmentMechanical Engineering Program
dc.contributor.departmentPhysical Science and Engineering (PSE) Division
dc.identifier.journalCombustion and Flame
dc.rights.embargodate2021-07-06
dc.eprint.versionPost-print
dc.contributor.institutionDepartment of Mechanical Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
kaust.personChung, Suk Ho
kaust.acknowledged.supportUnitKAUST Supercomputing Laboratory
dc.date.published-online2019-07-16
dc.date.published-print2019-10


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NOTICE: 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, [[Volume], [Issue], (2019-07-16)] DOI: 10.1016/j.combustflame.2019.07.011 . © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
Except where otherwise noted, this item's license is described as NOTICE: 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, [[Volume], [Issue], (2019-07-16)] DOI: 10.1016/j.combustflame.2019.07.011 . © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/