Flame interactions and burning characteristics of two live leaf samples1
Brent M. Pickett A , Carl Isackson A , Rebecca Wunder A , Thomas H. Fletcher A D , Bret W. Butler B and David R. Weise CA Department of Chemical Engineering, Brigham Young University, Provo, UT 84602, USA.
B USDA Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, MT 59808, USA.
C USDA Forest Service, Pacific Southwest Research Station, Forest Fire Laboratory, Riverside, CA 92507, USA.
D Corresponding author. Email: tom_fletcher@byu.edu
International Journal of Wildland Fire 18(7) 865-874 https://doi.org/10.1071/WF08143
Submitted: 12 August 2008 Accepted: 22 December 2008 Published: 27 October 2009
Abstract
Combustion experiments were performed over a flat-flame burner that provided the heat source for multiple leaf samples. Interactions of the combustion behavior between two leaf samples were studied. Two leaves were placed in the path of the flat-flame burner, with the top leaf 2.5 cm above the bottom leaf. Local gas and particle temperatures, as well as local oxygen concentrations, were measured along with burning characteristics of both leaves. Results showed that the time to ignition of the upper leaf was not significantly affected by the presence of the lower leaf. The major difference observed was that the time of flame duration of the upper leaf was significantly affected by the presence of the lower leaf. Causes for the prolonged flame were found to be the consumption of oxygen by the burning lower leaf and the obstruction provided by the lower leaf, causing a wake effect, thus altering the combustion behavior of the upper leaf.
Acknowledgements
This research was funded by the USDA/USDI National Fire Plan administered through a Research Joint Venture Agreement (No. 01-CR-11272166–060) with collaboration with the Forest Fire Laboratory, Pacific Southwest Research Station, USDA Forest Service, Riverside, CA, and the Forest Fire Laboratory, Rocky Mountain Research Station, USDA Forest Service, Missoula, MT. Special thanks to Joey Chong from the Riverside Forest Fire Laboratory, who helped with the collection of chaparral samples.
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1 Part of this manuscript was prepared by US Government employees on official time and with government funding and is therefore in the public domain and not subject to copyright in the US.
2 Source for common and scientific plant names – USDA plants database: http://plants.usda.gov, accessed 29 September 2009.