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Flame Extensions Under a Curved Ceiling

Sturdy, Martin and Johansson, Nils LU orcid (2025) In Fire Technology
Abstract

In this paper, the factors affecting flame extension under curved ceilings are presented. An experimental campaign in reduced scale was carried out in Lund University’s Fire Lab using a propane gas burner and heptane pool fire in different positions and heat release rates within a curved ceiling setup. A flame recognition script was developed to identify the flame length in the videos taken for each test. The flame length data was then compared with flame length models found in the literature which have only been developed from buoyancy driven flows. The results show that the curved geometry affects flow, enhancing it and resulting in longer flames. This is particularly clear in the tests with the propane gas burner. When positioned... (More)

In this paper, the factors affecting flame extension under curved ceilings are presented. An experimental campaign in reduced scale was carried out in Lund University’s Fire Lab using a propane gas burner and heptane pool fire in different positions and heat release rates within a curved ceiling setup. A flame recognition script was developed to identify the flame length in the videos taken for each test. The flame length data was then compared with flame length models found in the literature which have only been developed from buoyancy driven flows. The results show that the curved geometry affects flow, enhancing it and resulting in longer flames. This is particularly clear in the tests with the propane gas burner. When positioned flush against the side wall, the reduced air entrainment and the gas’s momentum cause unburnt fuel to travel further along the ceiling, thereby extending the flame length. In the case of pool fires, proximity to the wall reduces the heat release rate which in turn limits the flame extensions. Consequently, momentum dominated flows such as those produced by the propane burner, result in longer flame extension compared to the buoyancy dominated flows characteristic of pool fires. The greatest difference between the experimental data presented in this study and flame extension models found in the literature is attributed to the omission of the flow’s buoyancy component in these models. Additionally, the type of fire, whether buoyancy or momentum dominated, and its position within the test setup impact the flame extensions. To address these limitations, this work introduces adaptations of previously published models.

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Please use this url to cite or link to this publication:
author
and
organization
publishing date
type
Contribution to journal
publication status
epub
subject
keywords
Buoyancy component, Curved ceiling, Flame extensions, Momentum dominated flow, Unburnt fuel
in
Fire Technology
article number
104780
pages
18 pages
publisher
Springer
external identifiers
  • scopus:105003479342
ISSN
0015-2684
DOI
10.1007/s10694-025-01735-9
language
English
LU publication?
yes
additional info
Publisher Copyright: © The Author(s) 2025.
id
e0253710-c61c-4698-a2f3-6690f3edfc50
date added to LUP
2025-05-13 23:25:10
date last changed
2025-06-10 09:27:42
@article{e0253710-c61c-4698-a2f3-6690f3edfc50,
  abstract     = {{<p>In this paper, the factors affecting flame extension under curved ceilings are presented. An experimental campaign in reduced scale was carried out in Lund University’s Fire Lab using a propane gas burner and heptane pool fire in different positions and heat release rates within a curved ceiling setup. A flame recognition script was developed to identify the flame length in the videos taken for each test. The flame length data was then compared with flame length models found in the literature which have only been developed from buoyancy driven flows. The results show that the curved geometry affects flow, enhancing it and resulting in longer flames. This is particularly clear in the tests with the propane gas burner. When positioned flush against the side wall, the reduced air entrainment and the gas’s momentum cause unburnt fuel to travel further along the ceiling, thereby extending the flame length. In the case of pool fires, proximity to the wall reduces the heat release rate which in turn limits the flame extensions. Consequently, momentum dominated flows such as those produced by the propane burner, result in longer flame extension compared to the buoyancy dominated flows characteristic of pool fires. The greatest difference between the experimental data presented in this study and flame extension models found in the literature is attributed to the omission of the flow’s buoyancy component in these models. Additionally, the type of fire, whether buoyancy or momentum dominated, and its position within the test setup impact the flame extensions. To address these limitations, this work introduces adaptations of previously published models.</p>}},
  author       = {{Sturdy, Martin and Johansson, Nils}},
  issn         = {{0015-2684}},
  keywords     = {{Buoyancy component; Curved ceiling; Flame extensions; Momentum dominated flow; Unburnt fuel}},
  language     = {{eng}},
  publisher    = {{Springer}},
  series       = {{Fire Technology}},
  title        = {{Flame Extensions Under a Curved Ceiling}},
  url          = {{http://dx.doi.org/10.1007/s10694-025-01735-9}},
  doi          = {{10.1007/s10694-025-01735-9}},
  year         = {{2025}},
}