Abstract
The various physical processes which affect the rate-of-spread of fires on surface fuel beds are discussed. Specifically, these include conduction, radiation from the flame and burning fuel bed, and convective heating influenced by wind. A new interpretation of a laboratory experiment is given, and from this a balance between radiative heating from the flame and convective cooling of the fuel bed is established. The ratio between these two effects may be expressed as a new dimensionless number, P (defined by equation 5.12 or 5.16). If P < 1, radiation from the flame of the fire alone is not capable of causing the fire to spread, whereas if P #> 1, generally it is. Many laboratory experiments have P < 1, whereas P #> 1 for moderate to large fires in the field. The most significant factor affecting fire propagation is wind, which increases both radiative and convective heating. Much of this process is turbulent and involves large eddies in the boundary layer and fuel canopy, and their interaction with fires is currently poorly understood.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.