Abstract
Smoldering combustion of natural organic layers like peatlands leads to the largest fires on Earth. Smoldering wildlfires may propagate slowly for several months, consuming organic matter and threatening to release ancient carbon stored deep in the soil. It has become a topic of global interest linked to ecosystem perturbations, carbon sequestration and climate change. Although experimental studies have revealed the main factors affecting ignition and spread of natural smoldering, there is little modeling work explaining these experiments. This study aims at bridging the gap by developing a numerical model of smoldering combustion spreading downwards through a column of organic soil. Two spreading fronts are considered, drying and combustion, fed by oxygen diffusion through the top ash layer. The model predicts the transient evolution of the temperature profiles in a vertical column, and the smoldering rate for organic soils with different properties. The role of moisture content, inorganic content, bulk density and heat of smoldering combustion in the critical conditions for self-sustained propagation is investigated. The simulation results show that the critical moisture content increases linearly with heat of smoldering combustion, decreases linearly with the inorganic content and decreases with organic bulk density. These results are consistent with previous experimental observations, indicating the model is capable for guiding further experimental studies.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.