Structure and propagation of spherical turbulent iron-methane hybrid flame at elevated pressure
(2023) In Combustion and Flame 255.- Abstract
In this communication we demonstrate the role of turbulence intensity in the dual-front structure and self-similar propagation of spherical turbulent iron-methane hybrid flames. We first show that iron-methane hybrid mixture, whose iron concentration is below a critical threshold for the formation of a dust flame front in laminar or weak turbulent environment, can be burned strongly with both separated dual-front and merged single-front structures in intense turbulence. It is suggested that the formation of iron flame front would be attributed to local iron concentration accumulation by preferential sampling with near-unity Stocks number (St), heat transfer enhancement of iron particles to fluid and mixing promotion of iron particles... (More)
In this communication we demonstrate the role of turbulence intensity in the dual-front structure and self-similar propagation of spherical turbulent iron-methane hybrid flames. We first show that iron-methane hybrid mixture, whose iron concentration is below a critical threshold for the formation of a dust flame front in laminar or weak turbulent environment, can be burned strongly with both separated dual-front and merged single-front structures in intense turbulence. It is suggested that the formation of iron flame front would be attributed to local iron concentration accumulation by preferential sampling with near-unity Stocks number (St), heat transfer enhancement of iron particles to fluid and mixing promotion of iron particles with oxidants by strong turbulence. The propagation of iron front falls behind the methane front in the leading segments which is promoted by flame stretch for sub-unity Lewis number (Le), thus the separated dual-front structure occurs. Furthermore, the strong self-similar propagation of spherical turbulent iron-methane hybrid flame was observed under different turbulence intensities (urms). Mechanistically, such strong self-similar propagation of the hybrid flame is the consequence of the couple effects of flame mode transition at high urms with near-unity St and differential diffusion for sub-unity Le.
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- author
- Cai, Xiao LU ; Su, Shouguo ; Su, Limin ; Wang, Jinhua ; Alden, Marcus LU ; Li, Zhongshan LU and Huang, Zuohua
- organization
- publishing date
- 2023-09
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Dual-front structure, Iron-methane hybrid flame, Self-similar propagation, Turbulent flame
- in
- Combustion and Flame
- volume
- 255
- article number
- 112918
- publisher
- Elsevier
- external identifiers
-
- scopus:85163501830
- ISSN
- 0010-2180
- DOI
- 10.1016/j.combustflame.2023.112918
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © 2023
- id
- f8a8e223-ade1-4cfe-8e6e-5500a4904f16
- date added to LUP
- 2023-08-22 08:17:09
- date last changed
- 2023-10-05 14:54:24
@article{f8a8e223-ade1-4cfe-8e6e-5500a4904f16,
abstract = {{<p>In this communication we demonstrate the role of turbulence intensity in the dual-front structure and self-similar propagation of spherical turbulent iron-methane hybrid flames. We first show that iron-methane hybrid mixture, whose iron concentration is below a critical threshold for the formation of a dust flame front in laminar or weak turbulent environment, can be burned strongly with both separated dual-front and merged single-front structures in intense turbulence. It is suggested that the formation of iron flame front would be attributed to local iron concentration accumulation by preferential sampling with near-unity Stocks number (St), heat transfer enhancement of iron particles to fluid and mixing promotion of iron particles with oxidants by strong turbulence. The propagation of iron front falls behind the methane front in the leading segments which is promoted by flame stretch for sub-unity Lewis number (Le), thus the separated dual-front structure occurs. Furthermore, the strong self-similar propagation of spherical turbulent iron-methane hybrid flame was observed under different turbulence intensities (u<sub>rms</sub>). Mechanistically, such strong self-similar propagation of the hybrid flame is the consequence of the couple effects of flame mode transition at high u<sub>rms</sub> with near-unity St and differential diffusion for sub-unity Le.</p>}},
author = {{Cai, Xiao and Su, Shouguo and Su, Limin and Wang, Jinhua and Alden, Marcus and Li, Zhongshan and Huang, Zuohua}},
issn = {{0010-2180}},
keywords = {{Dual-front structure; Iron-methane hybrid flame; Self-similar propagation; Turbulent flame}},
language = {{eng}},
publisher = {{Elsevier}},
series = {{Combustion and Flame}},
title = {{Structure and propagation of spherical turbulent iron-methane hybrid flame at elevated pressure}},
url = {{http://dx.doi.org/10.1016/j.combustflame.2023.112918}},
doi = {{10.1016/j.combustflame.2023.112918}},
volume = {{255}},
year = {{2023}},
}