Skip to page content
USDA Forest Service
  
Treesearch

Research & Development Treesearch

 
Treesearch Home
About Treesearch
Contact Us
Research & Development
Forest Products Lab
International Institute of Tropical Forestry
Northern
Pacific Northwest
Pacific Southwest
Rocky Mountain
Southern Research Station
Help
 

Science.gov - We Participate


USA.gov  Government Made Easy


Global Forest Information Service

US Forest Service
P.O. Box 96090
Washington, D.C.
20090-6090

(202) 205-8333

You are here: Home / Search / Publication Information
Bookmark and Share

Publication Information

View PDF (744 KB)

Title: Experimental modeling of crown fire initiation in open and closed shrubland systems

Author: Tachajapong, W.; Lozano, S.; Mahalingam, S.; Weise, D.R.;

Date: 2014

Source: International Journal of Wildland Fire 23: 451-462

Publication Series: Scientific Journal (JRNL)

Description: The transition of surface fire to live shrub crown fuels was studied through a simplified laboratory experiment using an open-topped wind tunnel. Respective surface and crown fuels used were excelsior (shredded Populus tremuloides wood) and live chamise (Adenostoma fasciculatum, including branches and foliage). A high crown fuel bulk density of 6.8 kgm-3 with a low crown fuel base height of 0.20m was selected to ensure successful crown fire initiation. Diagnostics included flame height and surface fire evolution. Experimental results were compared with similar experiments performed in an open environment, in which the side walls of the wind tunnel were removed. The effect of varying wind speed in the range 0–1.8ms-1, representing a Froude number range of 0–1.1, on crown fire initiation was investigated. The suppression of lateral entrainment due to wind tunnel walls influenced surface fire behavior. When wind speed increased from 1.5 to 1.8ms-1, the rate of spread of surface fire and surface fire depth increased from 5.5 to 12.0 cm s-1 and 0.61 to 1.02 m. As a result, the residence time of convective heating significantly increased from 16.0 to 24.0 s and the hot gas temperature at the crown base increased from 994 to 1141 K. The change in surface fire characteristics significantly affected the convective energy transfer process. Thus, the net energy transfer to the crown fuel increased so the propensity for crown fire initiation increased. In contrast, increasing wind speed decreased the tendency for crown fuel initiation in an open environment because of the cooling effect from fresh air entrainment via the lateral sides of surface fire.

Keywords: fire behavior, fire prevention

Publication Notes:

  • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
  • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.

XML: View XML

Citation:


Tachajapong, W.; Lozano, S.; Mahalingam, S.; Weise, D.R. 2014 Experimental modeling of crown fire initiation in open and closed shrubland systems. International Journal of Wildland Fire 23: 451-462, doi:10.1071/WF12118

 


 [ Get Acrobat ]  Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility

USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.