Laminar burning velocities of rich CH4+N2+O2 flames : A projection to make direct data comparison for highly dispersed experimental conditions
(2026) In Combustion and Flame 283.- Abstract
The laminar burning velocity (SL) of methane (CH4), the primary constituent of natural gas, is a key combustion property essential for validating combustion kinetic models. The present study focuses on the CH4 SL at the very rich side of flames, where the available experimental data are scarce with highly dispersed measurement conditions, and data projection was carried out to overcome the difficulty in making direct data comparison and subsequent kinetic model validation. To validate the projection method, new measurements were performed across various equivalence ratios (1.6 - 2.3), unburnt temperatures (298 K - 448 K), and oxygen ratios in the O2+N2 oxidizer (0.30 -... (More)
The laminar burning velocity (SL) of methane (CH4), the primary constituent of natural gas, is a key combustion property essential for validating combustion kinetic models. The present study focuses on the CH4 SL at the very rich side of flames, where the available experimental data are scarce with highly dispersed measurement conditions, and data projection was carried out to overcome the difficulty in making direct data comparison and subsequent kinetic model validation. To validate the projection method, new measurements were performed across various equivalence ratios (1.6 - 2.3), unburnt temperatures (298 K - 448 K), and oxygen ratios in the O2+N2 oxidizer (0.30 - 0.38), with many conditions not explored in existing literature. Six widely-used kinetic models were adopted for simulations, together with reaction sensitivity analyses, which revealed consistent reactions governing the SL dependences on the unburnt temperatures and oxygen ratios. Similar flame conditions with nearly identical A-factor SL sensitivity values were also identified, with a parameter ζA−B introduced to describe the SL ratio between conditions A and B within a similar flame condition area. The very low reaction sensitivities of ζA−B allow any model to accurately reflect ζA−B regardless of its accuracy in predicting SL. Using the simulated ζA−B, all available data at 1 atm were projected to conditions with unburnt temperature 377 K and various oxygen ratios, through which inconsistencies among different experimental datasets were revealed, indicating some of the measurements should have larger actual uncertainties than reported. Moreover, all six models significantly underestimate the SL for flames with an equivalence ratio of 1.5 and low oxygen ratios and overestimate the equivalence ratio 2.5 results, indicating room for further improvement of these models. Besides, the projection method proposed in the present study can potentially be applied to other types of flames, helping data comparison and kinetic model validation.
(Less)
- author
- Han, Xinlu LU ; Lin, Fawei and Konnov, Alexander A. LU
- organization
- publishing date
- 2026-01
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Elevated temperature, Laminar burning velocity, Methane, Oxygen enriched combustion, Very-rich
- in
- Combustion and Flame
- volume
- 283
- article number
- 114617
- publisher
- Elsevier
- external identifiers
-
- scopus:105021879854
- ISSN
- 0010-2180
- DOI
- 10.1016/j.combustflame.2025.114617
- language
- English
- LU publication?
- yes
- id
- 161aef58-d0e0-4fbc-b057-cdf847259a2a
- date added to LUP
- 2026-02-11 11:45:37
- date last changed
- 2026-02-17 08:50:09
@article{161aef58-d0e0-4fbc-b057-cdf847259a2a,
abstract = {{<p>The laminar burning velocity (S<sub>L</sub>) of methane (CH<sub>4</sub>), the primary constituent of natural gas, is a key combustion property essential for validating combustion kinetic models. The present study focuses on the CH<sub>4</sub> S<sub>L</sub> at the very rich side of flames, where the available experimental data are scarce with highly dispersed measurement conditions, and data projection was carried out to overcome the difficulty in making direct data comparison and subsequent kinetic model validation. To validate the projection method, new measurements were performed across various equivalence ratios (1.6 - 2.3), unburnt temperatures (298 K - 448 K), and oxygen ratios in the O<sub>2</sub>+N<sub>2</sub> oxidizer (0.30 - 0.38), with many conditions not explored in existing literature. Six widely-used kinetic models were adopted for simulations, together with reaction sensitivity analyses, which revealed consistent reactions governing the S<sub>L</sub> dependences on the unburnt temperatures and oxygen ratios. Similar flame conditions with nearly identical A-factor S<sub>L</sub> sensitivity values were also identified, with a parameter ζ<sub>A−B</sub> introduced to describe the S<sub>L</sub> ratio between conditions A and B within a similar flame condition area. The very low reaction sensitivities of ζ<sub>A−B</sub> allow any model to accurately reflect ζ<sub>A−B</sub> regardless of its accuracy in predicting S<sub>L</sub>. Using the simulated ζ<sub>A−B</sub>, all available data at 1 atm were projected to conditions with unburnt temperature 377 K and various oxygen ratios, through which inconsistencies among different experimental datasets were revealed, indicating some of the measurements should have larger actual uncertainties than reported. Moreover, all six models significantly underestimate the S<sub>L</sub> for flames with an equivalence ratio of 1.5 and low oxygen ratios and overestimate the equivalence ratio 2.5 results, indicating room for further improvement of these models. Besides, the projection method proposed in the present study can potentially be applied to other types of flames, helping data comparison and kinetic model validation.</p>}},
author = {{Han, Xinlu and Lin, Fawei and Konnov, Alexander A.}},
issn = {{0010-2180}},
keywords = {{Elevated temperature; Laminar burning velocity; Methane; Oxygen enriched combustion; Very-rich}},
language = {{eng}},
publisher = {{Elsevier}},
series = {{Combustion and Flame}},
title = {{Laminar burning velocities of rich CH<sub>4</sub>+N<sub>2</sub>+O<sub>2</sub> flames : A projection to make direct data comparison for highly dispersed experimental conditions}},
url = {{http://dx.doi.org/10.1016/j.combustflame.2025.114617}},
doi = {{10.1016/j.combustflame.2025.114617}},
volume = {{283}},
year = {{2026}},
}