Citation

Sullivan AL, Swedosh W, Hurley RJ, Sharples JJ, Hilton JE. Int. J. Wildland Fire 2019; 28(9): 704-719.

Copyright

(Copyright © 2019, International Association of Wildland Fire, Fire Research Institute, Publisher CSIRO Publishing)

DOI

10.1071/WF18217

PMID

unavailable

Abstract

Quantification of the interaction of intersecting and non-intersecting fire perimeters over a range of shapes, sizes and orientations is essential to understanding the behaviour of high-intensity wildfires that have become discontiguous as a result of spot fires or effects of broken topography or fuels. One key configuration is that of the V-shaped fire where two individual lines of fire intersect at oblique angles. Previous work under calm conditions in pine needle litter and straw found the speed of propagation of the vertex of the intersection to increase non-linearly as the angle of intersection decreased. The present paper investigates this relation in dry eucalypt forest litter in both the absence and presence of wind (~1.0 m s−1) and found that the increase in vertex speed under calm conditions was no greater than would be expected due to the geometry of the configuration. Conversely, in the presence of wind, the increase in the vertex propagation speed was substantially greater than explained by the geometry alone. Although these results suggest that fire line interactions can influence the behaviour and spread of coalescing fire fronts, further research is required to both identify the precise mechanisms driving this behaviour and quantify the resultant effects.

Additional keywords: experiment, fire behaviour, fire spread, laboratory, Pyrotron, rate of spread, spot fire, wildfire.

Language: en