Fire spread across forest fuel is usually characterized by the rate of spread or the fireline intensity.The determination of the fireline intensity represents an essential aspect for understanding the behaviour of the fire and the involved combustion processes. The heat released during fire spread cannot be a-priori estimated from the fundamental properties of the fuel material and experiments need to be carried out to determine it. This paper presents a global characterization of horizontal fire spread in still air across fuel beds in terms of heat release, rate of spread, flame geometry and radiant and convective fractions. The influence of the fuel load on these main fire properties is investigated.A series of experiments was conducted using a Large Scale Heat Release apparatus. The fire tests were carried out on a combustion table located on a load cell. The fuel consisted in a 2 m long and 1 m wide bed of pine needles. The fireline intensity was accurately estimated by means of oxygen consumption calorimetry and some other methods to assess this quantity were also tested.Combustion efficiency and effective heat of combustion were discussed. The heat fluxes emitted during the fire spread were also investigated. In the studied configuration, radiation was the dominant heat transfer mechanism in the preheating zone; whereas some transfers combining

Skeletal and global mechanisms for the combustion of gases released by crushed forest fuelsCitation for published version: Tihay, V, Santoni, P-A, Simeoni, A, Garo, J-P & Vantelon, J-P 2009, 'Skeletal and global mechanisms for the combustion of gases released by crushed forest fuels ' Combustion and flame, vol. 156, no. 8, pp. 1565-1575. DOI: 10.1016/j.combustflame.2009 General rightsCopyright for the publications made accessible via the Edinburgh Research Explorer is retained by the author(s) and / or other copyright owners and it is a condition of accessing these publications that users recognise and abide by the legal requirements associated with these rights. Take down policyThe University of Edinburgh has made every reasonable effort to ensure that Edinburgh Research Explorer content complies with UK legislation. If you believe that the public display of this file breaches copyright please contact openaccess@ed.ac.uk providing details, and we will remove access to the work immediately and investigate your claim. Shortened Title: Gas combustion modelling for forest fuels Abstract:This study aims to improve the description of the gas phase combustion in physical models of forest fire spreading. The current models liken the degradation gases of forest fuels to carbon monoxide burning in air, whatever vegetation species. The first part of the study was devoted to determine whether the degradation gases have to be considered accurately in forest fire modelling. A laboratory experimental apparatus was designed to study the influence of the degradation gases on the laminar flames from crushed forest fuels. Thanks to these experiments, the role of the degradation gases on the gas phase combustion was highlighted.The second part was dedicated to improve the combustion models of degradation gases.

No abstract

Smouldering of the forest subsurface can be responsible for a large fraction of the total fuel consumed during wildfires. Subsurface fires can take place in organic material stored in shallow forest layers such as duff or humus, and in deeper layers such as peat, landfills and coal seams. These fires play a major role in the global emission to the atmosphere, the destruction of carbon storage in the soil and the damage to the natural environment. Burning dynamics in two different ecosystems affected by smouldering wildfires are studied here; boreal peat and Mediterranean humus. A series of small-scale smouldering experiments have been conducted under laboratory conditions to study the ignition and the severity to the soil. The experimental set-up allowed the temperature and velocity of the fire front to be measured for different fuel moisture contents. The two fuels, peat and humus, were tested and the results are compared.