Propagation and extinction of subatmospheric counterflow methane flames.
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| Title: | Propagation and extinction of subatmospheric counterflow methane flames. |
|---|---|
| Authors: | Burrell, Robert R.1 rburrell@usc.edu, Lee, Dong J.1, Egolfopoulos, Fokion N.1 |
| Source: | Combustion & Flame. Sep2018, Vol. 195, p117-127. 11p. |
| Subjects: | Counterflows (Fluid dynamics), Methane flames, Combustion, Strain rate, High pressure (Technology) |
| Abstract: | Measurements of flame propagation velocities and extinction states in counterflow provide a valuable source of flame data that contain information about fundamental combustion physics. The approach to properly account for stretch effects in counterflow flame measurements through non-intrusive laser-based local velocity characterization was advanced in the mid-80s by Law and coworkers at atmospheric conditions with simple fuels. Subsequently, several research groups have extended the measurements to elevated pressures and complex fuels. However, counterflow flame data at subatmospheric pressures are limited. In the present study, a method is introduced for measuring laminar flame speeds and extinction strain rates in subatmospheric counterflow flames. A numerical study was performed to assess the dynamics of tracer particles used to facilitate measurements. It was found that the particle phase dynamics used in particle velocimetry measurements are not always representative of the underlying gas phase motion due to thermophoresis and insufficient drag, especially at low pressures. A numerical scheme was implemented whereby the computed particle phases were used for proper comparison with measurements and, based on the computed results, to infer the corresponding values of the gas phase. The method was applied to premixed methane/air and non-premixed methane–nitrogen/oxygen flames at pressures as low as 0.1 atm. Complimentary flame structure simulations were carried out which show that the kinetics of formyl radical prompt dissociation strongly impact the computed subatmospheric flames and may influence the validation of unimolecular and bimolecular reactions rate constants when tested against laminar flame data. [ABSTRACT FROM AUTHOR] |
| Copyright of Combustion & Flame is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 130690626 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Propagation and extinction of subatmospheric counterflow methane flames. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Burrell%2C+Robert+R%2E%22">Burrell, Robert R.</searchLink><relatesTo>1</relatesTo><i> rburrell@usc.edu</i><br /><searchLink fieldCode="AR" term="%22Lee%2C+Dong+J%2E%22">Lee, Dong J.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Egolfopoulos%2C+Fokion+N%2E%22">Egolfopoulos, Fokion N.</searchLink><relatesTo>1</relatesTo> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Combustion+%26+Flame%22">Combustion & Flame</searchLink>. Sep2018, Vol. 195, p117-127. 11p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Counterflows+%28Fluid+dynamics%29%22">Counterflows (Fluid dynamics)</searchLink><br /><searchLink fieldCode="DE" term="%22Methane+flames%22">Methane flames</searchLink><br /><searchLink fieldCode="DE" term="%22Combustion%22">Combustion</searchLink><br /><searchLink fieldCode="DE" term="%22Strain+rate%22">Strain rate</searchLink><br /><searchLink fieldCode="DE" term="%22High+pressure+%28Technology%29%22">High pressure (Technology)</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Measurements of flame propagation velocities and extinction states in counterflow provide a valuable source of flame data that contain information about fundamental combustion physics. The approach to properly account for stretch effects in counterflow flame measurements through non-intrusive laser-based local velocity characterization was advanced in the mid-80s by Law and coworkers at atmospheric conditions with simple fuels. Subsequently, several research groups have extended the measurements to elevated pressures and complex fuels. However, counterflow flame data at subatmospheric pressures are limited. In the present study, a method is introduced for measuring laminar flame speeds and extinction strain rates in subatmospheric counterflow flames. A numerical study was performed to assess the dynamics of tracer particles used to facilitate measurements. It was found that the particle phase dynamics used in particle velocimetry measurements are not always representative of the underlying gas phase motion due to thermophoresis and insufficient drag, especially at low pressures. A numerical scheme was implemented whereby the computed particle phases were used for proper comparison with measurements and, based on the computed results, to infer the corresponding values of the gas phase. The method was applied to premixed methane/air and non-premixed methane–nitrogen/oxygen flames at pressures as low as 0.1 atm. Complimentary flame structure simulations were carried out which show that the kinetics of formyl radical prompt dissociation strongly impact the computed subatmospheric flames and may influence the validation of unimolecular and bimolecular reactions rate constants when tested against laminar flame data. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Combustion & Flame is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1016/j.combustflame.2018.03.034 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 11 StartPage: 117 Subjects: – SubjectFull: Counterflows (Fluid dynamics) Type: general – SubjectFull: Methane flames Type: general – SubjectFull: Combustion Type: general – SubjectFull: Strain rate Type: general – SubjectFull: High pressure (Technology) Type: general Titles: – TitleFull: Propagation and extinction of subatmospheric counterflow methane flames. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Burrell, Robert R. – PersonEntity: Name: NameFull: Lee, Dong J. – PersonEntity: Name: NameFull: Egolfopoulos, Fokion N. IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 09 Text: Sep2018 Type: published Y: 2018 Identifiers: – Type: issn-print Value: 00102180 Numbering: – Type: volume Value: 195 Titles: – TitleFull: Combustion & Flame Type: main |
| ResultId | 1 |
