The impact of reactants composition and temperature on the flow structure in a wake stabilized laminar lean premixed CH4/H2/air flames; mechanism and scaling

Handle URI:
http://hdl.handle.net/10754/623606
Title:
The impact of reactants composition and temperature on the flow structure in a wake stabilized laminar lean premixed CH4/H2/air flames; mechanism and scaling
Authors:
Michaels, D.; Shanbhogue, S.J.; Ghoniem, A.F.
Abstract:
In this paper we investigate the role of reactants composition and temperature in defining the steady flow structure in bluff body stabilized premixed flames. The study was motivated by experiments which showed that the flow structure and stability map for different fuels and inlet conditions collapse using the extinction strain rate as the chemical time scale. The investigation is conducted using a laminar lean premixed flame stabilized on a heat conducting bluff-body. Calculations are performed for a wide range of mixtures of CH4/H2/air (0.35 ≤ ϕ ≤ 0.75, 0 ≤ %H2 ≤ 40, 300 ≤ Tin [K] ≤ 500) in order to systematically vary the burning velocity (2.0–35.6 cm/s), dilatation ratio (2.7–6.4), and extinction strain rate (106–2924 1/s). The model is based on a fully resolved unsteady two-dimensional flow with detailed chemistry and species transport, and with no artificial flame anchoring boundary conditions. Calculations reveal that the recirculation zone length correlates with a chemical time scale based on the flame extinction strain rate corresponding to the inlet fuel composition, stoichiometry, pressure and temperature; and are consistent with experimental data in literature. It was found that in the wake region the flame is highly stretched and its location and interaction with the flow is governed by the reactants combustion characteristics under high strain.
Citation:
Michaels D, Shanbhogue SJ, Ghoniem AF (2017) The impact of reactants composition and temperature on the flow structure in a wake stabilized laminar lean premixed CH 4 /H 2 /air flames; mechanism and scaling. Combustion and Flame 176: 151–161. Available: http://dx.doi.org/10.1016/j.combustflame.2016.10.007.
Publisher:
Elsevier BV
Journal:
Combustion and Flame
KAUST Grant Number:
KUS-110-010-01
Issue Date:
11-Nov-2016
DOI:
10.1016/j.combustflame.2016.10.007
Type:
Article
ISSN:
0010-2180
Sponsors:
This work was supported partly by a MIT-Technion fellowship to Dan Michaels and partly by KAUST grant number KUS-110-010-01.
Appears in Collections:
Publications Acknowledging KAUST Support

Full metadata record

DC FieldValue Language
dc.contributor.authorMichaels, D.en
dc.contributor.authorShanbhogue, S.J.en
dc.contributor.authorGhoniem, A.F.en
dc.date.accessioned2017-05-15T10:35:10Z-
dc.date.available2017-05-15T10:35:10Z-
dc.date.issued2016-11-11en
dc.identifier.citationMichaels D, Shanbhogue SJ, Ghoniem AF (2017) The impact of reactants composition and temperature on the flow structure in a wake stabilized laminar lean premixed CH 4 /H 2 /air flames; mechanism and scaling. Combustion and Flame 176: 151–161. Available: http://dx.doi.org/10.1016/j.combustflame.2016.10.007.en
dc.identifier.issn0010-2180en
dc.identifier.doi10.1016/j.combustflame.2016.10.007en
dc.identifier.urihttp://hdl.handle.net/10754/623606-
dc.description.abstractIn this paper we investigate the role of reactants composition and temperature in defining the steady flow structure in bluff body stabilized premixed flames. The study was motivated by experiments which showed that the flow structure and stability map for different fuels and inlet conditions collapse using the extinction strain rate as the chemical time scale. The investigation is conducted using a laminar lean premixed flame stabilized on a heat conducting bluff-body. Calculations are performed for a wide range of mixtures of CH4/H2/air (0.35 ≤ ϕ ≤ 0.75, 0 ≤ %H2 ≤ 40, 300 ≤ Tin [K] ≤ 500) in order to systematically vary the burning velocity (2.0–35.6 cm/s), dilatation ratio (2.7–6.4), and extinction strain rate (106–2924 1/s). The model is based on a fully resolved unsteady two-dimensional flow with detailed chemistry and species transport, and with no artificial flame anchoring boundary conditions. Calculations reveal that the recirculation zone length correlates with a chemical time scale based on the flame extinction strain rate corresponding to the inlet fuel composition, stoichiometry, pressure and temperature; and are consistent with experimental data in literature. It was found that in the wake region the flame is highly stretched and its location and interaction with the flow is governed by the reactants combustion characteristics under high strain.en
dc.description.sponsorshipThis work was supported partly by a MIT-Technion fellowship to Dan Michaels and partly by KAUST grant number KUS-110-010-01.en
dc.publisherElsevier BVen
dc.subjectLaminar premixed flameen
dc.subjectFuel compositionen
dc.subjectFlame flow interactionen
dc.subjectBluff body flameen
dc.titleThe impact of reactants composition and temperature on the flow structure in a wake stabilized laminar lean premixed CH4/H2/air flames; mechanism and scalingen
dc.typeArticleen
dc.identifier.journalCombustion and Flameen
dc.contributor.institutionDepartment of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USAen
kaust.grant.numberKUS-110-010-01en
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