Flame Extensions Under Ceilings
(2023) VBRM05 20231Division of Fire Safety Engineering
- Abstract
- In this Master thesis project the factors affecting flame extension under flat and curved ceilings have been investigated. An experimental campaign 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 the setups. A flame recognition Python 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 review. Results show that the flame extension under the curved ceiling were larger than under the flat ceiling: this is because the curved geometry affects the flow’s buoyancy component, enhancing it and resulting in larger flames.... (More)
- In this Master thesis project the factors affecting flame extension under flat and curved ceilings have been investigated. An experimental campaign 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 the setups. A flame recognition Python 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 review. Results show that the flame extension under the curved ceiling were larger than under the flat ceiling: this is because the curved geometry affects the flow’s buoyancy component, enhancing it and resulting in larger flames. Furthermore, the reduced entrainment of the side wall position makes unburnt fuel travel further under the ceiling extending the flame more. Differences in the flow characteristics also impacts the flame length: momentum driven flows such as that produced by the propane burner have a longer flame extension compared to the buoyancy driven flow of a pool fire. The greatest differences between the test data and the models found in literature result form the neglection of the flow’s buoyancy component. Different test setups, fuels and test configurations can also be the cause of the found discrepancies. Adaptations of the relations put forward by the literature for the test results were therefore found in this work. Further study into different fuel types and burner positions would provide more information regarding the fire’s behaviour beneath ceilings and keep structures and people inside them safe. (Less)
- Popular Abstract
- Fire is a big threat to the safety of individuals and structures. Each year several incidents occur and often casualties are recorded around the world due to accidents that involve fire. In particular, the flames of the fire can grow and spread from the area of origin to other parts of an enclosure and building. Flame extensions under ceilings need to therefore be studied extensively in order to prevent fire’s growth and propagation. In literature flame extensions beneath flat ceiling geometries have been extensively studied. Due to developments in architectural and building designs, more unique ceiling geometries and curved ceilings are becoming more common. For this reason, the flame extension phenomenon beneath curved ceilings needs to... (More)
- Fire is a big threat to the safety of individuals and structures. Each year several incidents occur and often casualties are recorded around the world due to accidents that involve fire. In particular, the flames of the fire can grow and spread from the area of origin to other parts of an enclosure and building. Flame extensions under ceilings need to therefore be studied extensively in order to prevent fire’s growth and propagation. In literature flame extensions beneath flat ceiling geometries have been extensively studied. Due to developments in architectural and building designs, more unique ceiling geometries and curved ceilings are becoming more common. For this reason, the flame extension phenomenon beneath curved ceilings needs to be investigated further.
In order to evaluate the effect of the ceiling geometry on the flame extensions beneath them, a series of tests were performed in the Fire Lab at Lund University using scale sized experimental setups characterized by flat and curved ceilings. The effect of the heat release rate of the fire, the type of fuel source and burner position inside the setup were analyzed in the tests. Thanks to the creation of an ad-hoc video analysis code using the Python programming language, the flame length was determined from the videos of each performed test. The flame length could therefore be compared to models that were found in literature that analyzed this quantity.
The flame length resulting from the flat ceiling tests was found to follow the models taken from literature with some error degree. These differences are attributed to differences in the test setups, fuels tested and measurement errors. For the curved ceiling case, the models that did not take into account the varying buoyancy component introduced by the curved geometry had the largest deviation from the test data. This parameter affects how the flame extends beneath the ceiling after impingement: the unburnt fuel needs to travel further before the ceiling before fully combusting. The closes representation of the test data was obtained from models that account for the changing buoyancy component beneath the curved ceiling. Linear regression was used to fit the test data more accurately and new equations were proposed. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9122092
- author
- Sturdy, Martin LU
- supervisor
- organization
- course
- VBRM05 20231
- year
- 2023
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- Flame length, curved ceiling
- report number
- 5698
- other publication id
- LUTVDG/TVBB—5698--SE
- language
- English
- id
- 9122092
- date added to LUP
- 2023-06-13 06:12:20
- date last changed
- 2023-06-13 06:12:20
@misc{9122092,
abstract = {{In this Master thesis project the factors affecting flame extension under flat and curved ceilings have been investigated. An experimental campaign 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 the setups. A flame recognition Python 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 review. Results show that the flame extension under the curved ceiling were larger than under the flat ceiling: this is because the curved geometry affects the flow’s buoyancy component, enhancing it and resulting in larger flames. Furthermore, the reduced entrainment of the side wall position makes unburnt fuel travel further under the ceiling extending the flame more. Differences in the flow characteristics also impacts the flame length: momentum driven flows such as that produced by the propane burner have a longer flame extension compared to the buoyancy driven flow of a pool fire. The greatest differences between the test data and the models found in literature result form the neglection of the flow’s buoyancy component. Different test setups, fuels and test configurations can also be the cause of the found discrepancies. Adaptations of the relations put forward by the literature for the test results were therefore found in this work. Further study into different fuel types and burner positions would provide more information regarding the fire’s behaviour beneath ceilings and keep structures and people inside them safe.}},
author = {{Sturdy, Martin}},
language = {{eng}},
note = {{Student Paper}},
title = {{Flame Extensions Under Ceilings}},
year = {{2023}},
}