Show simple item record

dc.contributor.authorCha, Min Suk
dc.contributor.authorSon, Jin Woo
dc.contributor.authorYoon, Sung Hwan
dc.contributor.authorLuong, Hung Truyen
dc.contributor.authorLacoste, Deanna
dc.contributor.authorSohn, Chae Hoon
dc.date.accessioned2018-10-29T10:45:56Z
dc.date.available2018-10-29T10:45:56Z
dc.date.issued2018-10-24
dc.identifier.citationCha MS, Son JW, Yoon SH, Luong HT, Lacoste DA, et al. (2019) Vortex formation mechanism within fuel streams in laminar nonpremixed jet flames. Combustion and Flame 199: 46–53. Available: http://dx.doi.org/10.1016/j.combustflame.2018.10.015.
dc.identifier.issn0010-2180
dc.identifier.doi10.1016/j.combustflame.2018.10.015
dc.identifier.urihttp://hdl.handle.net/10754/629453
dc.description.abstractA vortical structure occurring at the fuel stream in laminar nonpremixed jet flames was recently found and shown to have both a fluid-dynamic impact on the flow field and a possible influence on the flame stability and soot formation. We designed a systematic experiment and numerical simulation to investigate the physical mechanisms of this recirculation phenomenon in a coflow system. We hypothesized that a negative buoyancy, caused by the fuel jet being heavier than the ambient air, may play a significant role in the recirculation. Therefore, we experimentally varied the density of the fuel jet using a binary mixture of methane and n-butane, and tested the density of the coflow oxidizer by replacing nitrogen with carbon dioxide. Several fuel jet velocities, flame temperatures, and nozzle diameters were also studied to thoroughly investigate all parameters that might possibly affect the recirculation. As a result, we found that our modified Richardson number, which is based on the cold density difference between the fuel and the coflow, the flame length, and the jet momentum flux, explained the physical mechanism of the recirculation well, with Ri ∼60 being the critical value for formation of the recirculation. The negative buoyancy was the primary driving force behind the recirculation, while the jet momentum mitigated its formation.
dc.description.sponsorshipThe research reported in this publication was supported by funding from King Abdullah University of Science and Technology (KAUST), under Award Number BAS/1/1384-01-01. JWS and CHS were supported by Advanced Research Center Program (NRF-2013R1A5A1073861) through the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) contracted through Advanced Space Propulsion Research Center at Seoul National University.
dc.publisherElsevier BV
dc.relation.urlhttps://www.sciencedirect.com/science/article/pii/S0010218018304425
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, [, , (2018-10-24)] DOI: 10.1016/j.combustflame.2018.10.015 . © 2018. 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.subjectNonpremixed flame
dc.subjectNegative buoyancy
dc.subjectRecirculation
dc.subjectRichardson number
dc.titleVortex formation mechanism within fuel streams in laminar nonpremixed jet flames
dc.typeArticle
dc.contributor.departmentClean Combustion Research Center
dc.contributor.departmentMechanical Engineering Program
dc.contributor.departmentPhysical Science and Engineering (PSE) Division
dc.identifier.journalCombustion and Flame
dc.eprint.versionPost-print
dc.contributor.institutionDepartment of Mechanical Engineering, Sejong University, Seoul 05006, Republic of Korea
kaust.personCha, Min Suk
kaust.personYoon, Sung Hwan
kaust.personLacoste, Deanna
kaust.grant.numberBAS/1/1384-01-01
refterms.dateFOA2018-10-29T10:49:13Z
dc.date.published-online2018-10-24
dc.date.published-print2019-01


Files in this item

Thumbnail
Name:
CNF_vortex laminar diffusion_final accepted.pdf
Size:
38.83Mb
Format:
PDF
Description:
Accepted Manuscript

This item appears in the following Collection(s)

Show simple item record