A computational model of the structure and extinction of strained, opposed flow, premixed methane-air flames

Kee, Robert J.; Miller, James A.; Evans, Gregory H.; Dixon‐Lewis, G.

doi:10.1016/s0082-0784(89)80158-4

Cited by 457 publications

(182 citation statements)

References 11 publications

Supporting

Mentioning

177

Contrasting

Unclassified

Order By: Relevance

“…Thus, detailed chemistry and transport can be employed with manageable computational resources. Note that flames described by self-similar solutions have been very useful in fundamental studies of fuel conversion processes and flame properties [26,27]. It should be noted that such solutions are only valid in the region near the axis of symmetry in the reactor, as has been demonstrated for this reactor configuration [28].…”

Section: Physical Model and Solution Methodologymentioning

confidence: 99%

Laminar oxy-fuel diffusion flame supported by an oxygen-permeable-ion-transport membrane

Hong

Kirchen

Ghoniem

2013

Combustion and Flame

View full text Add to dashboard Cite

A numerical model with detailed gas-phase chemistry and transport was used to predict homogeneous fuel conversion processes and to capture the important features (e.g., the location, temperature, thickness and structure of a flame) of laminar oxy-fuel diffusion flames stabilized on the sweep side of an oxygen permeable ion transport membrane (ITM). We assume that the membrane surface is not catalytic to hydrocarbon or syngas oxidation. It has been demonstrated that an ITM can be used for hydrocarbon conversion with enhanced reaction selectivity such as oxy-fuel combustion for carbon capture technologies and syngas production. Within an ITM unit, the oxidizer flow rate, i.e., the oxygen permeation flux, is not a pre-determined quantity, since it depends on the oxygen partial pressures on the feed and sweep sides and the membrane temperature. Instead, it is influenced by the oxidation reactions that are also dependent on the oxygen permeation rate, the initial conditions of the sweep gas, i.e., the fuel concentration, flow rate and temperature, and the diluent. In oxy-fuel combustion applications, the sweep side is fuel-diluted with CO2, and the entire unit is preheated to achieve a high oxygen permeation flux. This study focuses on the flame structure under these conditions and specifically on the chemical effect of CO2 dilution. Results show that, when the fuel diluent is CO2, a diffusion flame with a lower temperature and a larger thickness is established in the vicinity of the membrane, in comparison with the case in which N2 is used as a diluent. Enhanced OH-driven reactions and suppressed H radical chemistry result in the formation of products with larger CO and H2O and smaller H2 concentrations. Moreover, radical concentrations are reduced due to the high CO2 fraction in the sweep gas. CO2 dilution reduces CH3 formation and slows down the formation of soot precursors, C2H2 and * Corresponding author. Tel.: +1 617 253 2295; Fax: +1 617 253 5981 Email address: ghoniem@mit.edu (Ahmed F. Ghoniem) 2 C2H4. The flame location impacts the species diffusion and heat transfer from the reaction zone towards the membrane, which affects the oxygen permeation rate and the flame temperature.

show abstract

Section: Physical Model and Solution Methodologymentioning

confidence: 99%

Laminar oxy-fuel diffusion flame supported by an oxygen-permeable-ion-transport membrane

Hong

Kirchen

Ghoniem

2013

Combustion and Flame

View full text Add to dashboard Cite

show abstract

“…(11), using the same computer code LFLAM, developed at Ciemat. The fuel and In physical space, we solve the continuity, momentum, species and temperature equations as described in [43,44] for the planar geometry, here written in their unsteady form (in this formulation F = ρu and G = −ρv/y with u the axial and v the normal velocity components and y the perpendicular direction):…”

Section: Numerical Resolution Of 1d Flameletsmentioning

confidence: 99%

RANS modelling of a lifted H2/N2 flame using an unsteady flamelet progress variable approach with presumed PDF

Naud

Novella

Pastor

et al. 2015

Combustion and Flame

View full text Add to dashboard Cite

Elsevier Naud, B.; Novella Rosa, R.; Pastor Enguídanos, JM.; Winklinger, JF. (2015). RANS modelling of a lifted H2/N2 flame using an unsteady flamelet progress variable approach with presumed PDF. Combustion and Flame. 162 (4) AbstractAn unsteady flamelet / progress variable (UFPV) approach is used to model a lifted H 2 /N 2 flame in a RANS framework together with presumed PDF. We solve the unsteady flamelets both in physical space and in mixture fraction space. We show that in the former case, the scalar dissipation rate profile strongly varies in time (while it is assumed to be fixed in time in the latter). However, this does not result in significant qualitative differences in the corresponding flamelet libraries. The progress variable is carefully defined, including both the main combustion product (H 2 O) and a key radical species in ignition process (HO 2 ). The presumed-PDF model is proposed in terms of the non-normalised progress variable, without assuming its statistical independence with mixture fraction. We introduce a modelled transport equation for the mean progress variable which is consistent with the basic underlying UFPV assumption, derived from the Lagrangian flamelet model. The influence of different model parameters on the results for the mean temperature and mean species mass fractions and their fluctuations is discussed. Good results are obtained for the conditions of the considered lifted flame where detailed experimental data is available. However, at low coflow temperature the modelled flame lift-off height is shorter than expected.

show abstract

“…1 (left column). Because of the small size of the nozzles, their close placement relative to one another, and the parabolic outflow velocity boundary condition, the strained diffusion flame considered here, strictly speaking, cannot be accurately described by the commonly used one-dimensional model [29,30]. The flame structure found along the axis of symmetry is shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

Two-dimensional direct numerical simulation of opposed-jet hydrogen/air flames: Transition from a diffusion to an edge flame

Lee

Frouzakis

Boulouchos

2000

Proceedings of the Combustion Institute

View full text Add to dashboard Cite

A computational model of the structure and extinction of strained, opposed flow, premixed methane-air flames

Cited by 457 publications

References 11 publications

Laminar oxy-fuel diffusion flame supported by an oxygen-permeable-ion-transport membrane

Laminar oxy-fuel diffusion flame supported by an oxygen-permeable-ion-transport membrane

RANS modelling of a lifted H2/N2 flame using an unsteady flamelet progress variable approach with presumed PDF

Two-dimensional direct numerical simulation of opposed-jet hydrogen/air flames: Transition from a diffusion to an edge flame

Contact Info

Product

Resources

About