Published works

Published works

Analysis Of The Physical Processes Associated With Junction Fires At Laboratory And Field Scales

TitleAnalysis Of The Physical Processes Associated With Junction Fires At Laboratory And Field Scales
Publication TypeJournal Article
Year of Publication2018
AuthorsRaposo, JR, Viegas, DX, Xie, X, Almeida, M, Figueiredo, AR, Porto, L, Sharples, J
JournalInternational Journal of Wildland Fire
Volume27
Issue1
Date Published01/2018
Keywordsaccelerating fires, convective effects, dynamic fire behaviour, extreme fire behaviour, Fire behaviour, merging fires.
Abstract

Junction fires, which involve the merging of two linear fire fronts intersecting at a small angle, are associated with very intense fire behaviour. The dynamic displacement of the intersection point of the two lines and the flow along the symmetry plane of the fire are analysed for symmetric boundary conditions. It is observed that the velocity of displacement of this point increases very rapidly owing to strong convective effects created by the fire that are similar to those of an eruptive fire. The change of fire geometry and of its associated flow gradually blocks the rate of spread increase and creates a strong deceleration of the fire, which ends up behaving like a linear fire front. Results from laboratory and field-scale experiments, using various fuel beds and slope angles and from a large-scale fire show that the processes are similar at a wide range of scales with little dependence on the initial boundary conditions. Numerical simulation of the heat flux from two flame surfaces to an element of the fuel bed show that radiation can be considered as the main mechanism of fire spread only during the deceleration phase of the fire.

URLhttp://www.publish.csiro.au/WF/WF16173
DOI10.1071/WF16173
Refereed DesignationRefereed
AFAC17 logo

AFAC17 logo

All the resources from our 2017 conference

National research priorities for natural hazards

National research priorities for natural hazards

National priorities for research

The Sir Ivan fire. Photo: Nick Moir, Fairfax Media

The Sir Ivan fire. Photo: Nick Moir, Fairfax Media

Research findings from 2017 NSW fires

Four years of highlights

Bushfire planning with kids ebook