Impact of Equivalence Ratio on the Macrostructure of Premixed Swirling CH[subscript 4]/Air and CH[subscript 4]/O[subscript 2]/CO[subscript 2] Flames
Premixed CH[subscript 4]/O[subscript 2]/CO[subscript 2] flames (oxy-flames) and CH[subscript 4]/air flames (air-flames) were experimentally studied in a swirl-stabilized combustor. For comparing oxy and air flames, the same equivalence ratio and adiabatic flame temperature were used. CO[subscript 2]...
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| Format: | Article |
| Language: | en_US |
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American Society of Mechanical Engineers (ASME)
2017
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| Online Access: | http://hdl.handle.net/1721.1/108448 https://orcid.org/0000-0001-8730-272X |
| _version_ | 1826198298717847552 |
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| author | Watanabe, Hirotatsu Shanbhogue, Santosh J. Ghoniem, Ahmed F. Shanbhogue, Santosh Ghoniem, Ahmed F |
| author2 | Massachusetts Institute of Technology. Department of Mechanical Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Mechanical Engineering Watanabe, Hirotatsu Shanbhogue, Santosh J. Ghoniem, Ahmed F. Shanbhogue, Santosh Ghoniem, Ahmed F |
| author_sort | Watanabe, Hirotatsu |
| collection | MIT |
| description | Premixed CH[subscript 4]/O[subscript 2]/CO[subscript 2] flames (oxy-flames) and CH[subscript 4]/air flames (air-flames) were experimentally studied in a swirl-stabilized combustor. For comparing oxy and air flames, the same equivalence ratio and adiabatic flame temperature were used. CO[subscript 2] dilution was adjusted to attain the same adiabatic temperature for the oxy-flame and the corresponding air-flame while keeping the equivalence ratio and Reynolds number (=20,000) the same. For high equivalence ratios, we observed flames stabilized along the inner and outer shear layers of the swirling flow and sudden expansion, respectively, in both flames. However, one notable difference between the two flames appears as the equivalence ratio reaches 0.60. At this point, the outer shear layer flame disappears in the air-flame while it persists in the oxy-flame, despite the lower burning velocity of the oxy-flame. Prior PIV measurements (Ref. 9) showed that the strains along the outer shear layer are higher than along the inner shear layer. Therefore, the extinction strain rates in both flames were calculated using a counter-flow premixed twin flame configuration. Calculations at the equivalence ratio of 0.60 show that the extinction strain rate is higher in the oxy than in the air flame, which help explain why it persists on the outer shear layer with higher strain rate. It is likely that extinction strain rates contribute to the oxy-flame stabilization when air flame extinguish in the outer shear layer. However, the trend reverses at higher equivalence ratio, and the cross point of the extinction strain rate appears at equivalence ratio of 0.64. |
| first_indexed | 2024-09-23T11:02:41Z |
| format | Article |
| id | mit-1721.1/108448 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T11:02:41Z |
| publishDate | 2017 |
| publisher | American Society of Mechanical Engineers (ASME) |
| record_format | dspace |
| spelling | mit-1721.1/1084482022-10-01T00:45:33Z Impact of Equivalence Ratio on the Macrostructure of Premixed Swirling CH[subscript 4]/Air and CH[subscript 4]/O[subscript 2]/CO[subscript 2] Flames Impact of Equivalence Ratio on the Macrostructure of Premixed Swirling CH4/Air and CH4/O2/CO2 Flames Watanabe, Hirotatsu Shanbhogue, Santosh J. Ghoniem, Ahmed F. Shanbhogue, Santosh Ghoniem, Ahmed F Massachusetts Institute of Technology. Department of Mechanical Engineering Watanabe, Hirotatsu Shanbhogue, Santosh Ghoniem, Ahmed F Premixed CH[subscript 4]/O[subscript 2]/CO[subscript 2] flames (oxy-flames) and CH[subscript 4]/air flames (air-flames) were experimentally studied in a swirl-stabilized combustor. For comparing oxy and air flames, the same equivalence ratio and adiabatic flame temperature were used. CO[subscript 2] dilution was adjusted to attain the same adiabatic temperature for the oxy-flame and the corresponding air-flame while keeping the equivalence ratio and Reynolds number (=20,000) the same. For high equivalence ratios, we observed flames stabilized along the inner and outer shear layers of the swirling flow and sudden expansion, respectively, in both flames. However, one notable difference between the two flames appears as the equivalence ratio reaches 0.60. At this point, the outer shear layer flame disappears in the air-flame while it persists in the oxy-flame, despite the lower burning velocity of the oxy-flame. Prior PIV measurements (Ref. 9) showed that the strains along the outer shear layer are higher than along the inner shear layer. Therefore, the extinction strain rates in both flames were calculated using a counter-flow premixed twin flame configuration. Calculations at the equivalence ratio of 0.60 show that the extinction strain rate is higher in the oxy than in the air flame, which help explain why it persists on the outer shear layer with higher strain rate. It is likely that extinction strain rates contribute to the oxy-flame stabilization when air flame extinguish in the outer shear layer. However, the trend reverses at higher equivalence ratio, and the cross point of the extinction strain rate appears at equivalence ratio of 0.64. King Abdullah University of Science and Technology (Grant KUS- 110-010-01) 2017-04-27T14:50:49Z 2017-04-27T14:50:49Z 2015-06 Article http://purl.org/eprint/type/ConferencePaper 978-0-7918-5669-7 http://hdl.handle.net/1721.1/108448 Watanabe, Hirotatsu, Santosh J. Shanbhogue, and Ahmed F. Ghoniem. “Impact of Equivalence Ratio on the Macrostructure of Premixed Swirling CH [subscript 4]/Air and CH[subscript 4]/O[subscript 2]/CO[subscript 2] Flames.” ASME Turbo Expo 2015: Turbine Technical Conference and Exposition, 15-19 June, 2015, Montréal, Canada , ASME, 2015. https://orcid.org/0000-0001-8730-272X en_US http://dx.doi.org/10.1115/GT2015-43224 Proceedings of ASME Turbo Expo 2015: Turbine Technical Conference and Exposition GT2015 Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Society of Mechanical Engineers (ASME) American Society of Mechanical Engineers (ASME) |
| spellingShingle | Watanabe, Hirotatsu Shanbhogue, Santosh J. Ghoniem, Ahmed F. Shanbhogue, Santosh Ghoniem, Ahmed F Impact of Equivalence Ratio on the Macrostructure of Premixed Swirling CH[subscript 4]/Air and CH[subscript 4]/O[subscript 2]/CO[subscript 2] Flames |
| title | Impact of Equivalence Ratio on the Macrostructure of Premixed Swirling CH[subscript 4]/Air and CH[subscript 4]/O[subscript 2]/CO[subscript 2] Flames |
| title_full | Impact of Equivalence Ratio on the Macrostructure of Premixed Swirling CH[subscript 4]/Air and CH[subscript 4]/O[subscript 2]/CO[subscript 2] Flames |
| title_fullStr | Impact of Equivalence Ratio on the Macrostructure of Premixed Swirling CH[subscript 4]/Air and CH[subscript 4]/O[subscript 2]/CO[subscript 2] Flames |
| title_full_unstemmed | Impact of Equivalence Ratio on the Macrostructure of Premixed Swirling CH[subscript 4]/Air and CH[subscript 4]/O[subscript 2]/CO[subscript 2] Flames |
| title_short | Impact of Equivalence Ratio on the Macrostructure of Premixed Swirling CH[subscript 4]/Air and CH[subscript 4]/O[subscript 2]/CO[subscript 2] Flames |
| title_sort | impact of equivalence ratio on the macrostructure of premixed swirling ch subscript 4 air and ch subscript 4 o subscript 2 co subscript 2 flames |
| url | http://hdl.handle.net/1721.1/108448 https://orcid.org/0000-0001-8730-272X |
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