doi:10.3850/978-981-08-7724-8_14-03

ABSTRACT

Small scale laboratory experiments conducted in the Fire Propagation Apparatus calorimeter are presented to study the burning of Mediterranean pine needles (Pinus halepensis) under a wide range of conditions. Fresh live (45-55% Moisture Content (MC)), oven-dry live (1-3% MC), fresh dead (7-8% MC) and oven-dry dead (1-3% MC) samples are studied in a large set of more than 80 experiments with good repeatability. The use of a porous sample holder allows studying the ignition and burning of fuels for a range of heat and flow conditions that mimic those encountered in real fires. The results show that the most flammable fuels are fresh dead, followed by oven-dry dead and oven-dry live, and the least flammable fuel is fresh live needle sample. The differences observed cannot be explained in terms of the MC solely as the fuel internal structure matters. Moreover, the loss of volatiles and other changes to the needles produced during the oven drying process lead to significant differences in the burning behaviour. The presence of an imposed flow of air inside the fuel bed has no effect on the burning behaviour of fresh live samples but greatly affects dead and ovendry needles. Overall, the results show that fire physics and chemistry vary for each of the samples.

Keywords: Forest fuel, Wildland fires, Calorimetry, FPA, Pine needles.

© 2011 CPD Unit, University of Leeds