Over-rich combustion of CH4, C2H6, and C3H8 +air premixed flames investigated by the heat flux method and kinetic modeling
(2019) In Combustion and Flame 210. p.339-349- Abstract
An uncommon non-monotonic behavior of the temperature dependence of adiabatic laminar burning velocity has been found in over-rich methane+air flames at equivalence ratio, ϕ = 1.4. To find out the universality and reasons of this turning point, methane, ethane and propane + air flames are studied both experimentally by the heat flux method and numerically using GRI-mech, USC-mech, UCSD-mech, FFCM mech, and Aramco mech over ϕ = 0.6–1.8, at unburned temperatures up to 368 K, and atmospheric pressure. Results show that the over-rich phenomena stem from a unique flame structure, where, after the flame front, H2O is reduced to H2 and C2Hx (x>1) is oxidized to CO, causing the temperature overtone... (More)
An uncommon non-monotonic behavior of the temperature dependence of adiabatic laminar burning velocity has been found in over-rich methane+air flames at equivalence ratio, ϕ = 1.4. To find out the universality and reasons of this turning point, methane, ethane and propane + air flames are studied both experimentally by the heat flux method and numerically using GRI-mech, USC-mech, UCSD-mech, FFCM mech, and Aramco mech over ϕ = 0.6–1.8, at unburned temperatures up to 368 K, and atmospheric pressure. Results show that the over-rich phenomena stem from a unique flame structure, where, after the flame front, H2O is reduced to H2 and C2Hx (x>1) is oxidized to CO, causing the temperature overtone (super adiabatic flame temperature), while some key reactions important for flame propagation changing their sensitivity signs. Inside the flame front, the importance of CH3 overwhelms other radicals like OH and H. By these distinguishing features, a method using temperature overtone to identify accurate turning points of over-rich regime is demonstrated.
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- author
- Han, Xinlu LU ; Wang, Zhihua ; He, Yong ; Wang, Shixing ; Zhu, Yanqun and Konnov, Alexander A. LU
- organization
- publishing date
- 2019
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Laminar burning velocity, Over-rich regime, Super adiabatic flame temperature, Temperature dependence
- in
- Combustion and Flame
- volume
- 210
- pages
- 11 pages
- publisher
- Elsevier
- external identifiers
-
- scopus:85072249367
- ISSN
- 0010-2180
- DOI
- 10.1016/j.combustflame.2019.09.009
- language
- English
- LU publication?
- yes
- id
- 11ea5d1d-2e5f-408e-9716-0100a5317a09
- date added to LUP
- 2019-09-27 14:16:41
- date last changed
- 2022-04-18 18:03:43
@article{11ea5d1d-2e5f-408e-9716-0100a5317a09, abstract = {{<p>An uncommon non-monotonic behavior of the temperature dependence of adiabatic laminar burning velocity has been found in over-rich methane+air flames at equivalence ratio, ϕ = 1.4. To find out the universality and reasons of this turning point, methane, ethane and propane + air flames are studied both experimentally by the heat flux method and numerically using GRI-mech, USC-mech, UCSD-mech, FFCM mech, and Aramco mech over ϕ = 0.6–1.8, at unburned temperatures up to 368 K, and atmospheric pressure. Results show that the over-rich phenomena stem from a unique flame structure, where, after the flame front, H<sub>2</sub>O is reduced to H<sub>2</sub> and C<sub>2</sub>H<sub>x</sub> (x>1) is oxidized to CO, causing the temperature overtone (super adiabatic flame temperature), while some key reactions important for flame propagation changing their sensitivity signs. Inside the flame front, the importance of CH<sub>3</sub> overwhelms other radicals like OH and H. By these distinguishing features, a method using temperature overtone to identify accurate turning points of over-rich regime is demonstrated.</p>}}, author = {{Han, Xinlu and Wang, Zhihua and He, Yong and Wang, Shixing and Zhu, Yanqun and Konnov, Alexander A.}}, issn = {{0010-2180}}, keywords = {{Laminar burning velocity; Over-rich regime; Super adiabatic flame temperature; Temperature dependence}}, language = {{eng}}, pages = {{339--349}}, publisher = {{Elsevier}}, series = {{Combustion and Flame}}, title = {{Over-rich combustion of CH<sub>4</sub>, C<sub>2</sub>H<sub>6</sub>, and C<sub>3</sub>H<sub>8</sub> +air premixed flames investigated by the heat flux method and kinetic modeling}}, url = {{http://dx.doi.org/10.1016/j.combustflame.2019.09.009}}, doi = {{10.1016/j.combustflame.2019.09.009}}, volume = {{210}}, year = {{2019}}, }