Effectiveness of fuel reduction against surface fire propagation

Project Details

• Student(s): Charbel Karam, Charbel Farhat
• Advisor(s): Dr. Gilbert Accary
• Department: Industrial & Mechanical
• Academic Year(s): 2025-2026

Abstract

Reducing wildfire hazard and their consequences on peoples and structures cannot be supported by only increasing the firefighting means. One of the most effective means in reducing the level of risk of a wildfire is to reduce the fuel load. A fuel-break is an area where the amount of fuel is reduced either uniformly or randomly. In this context, two main questions are: (1) What fuel-reduction percentage in a fuel-break would stop a surface fire propagation when fuel is randomly or uniformly reduced? (2) What should be the fuel-break width for this threshold value of fuel-reduction percentage? To tackle this problem, numerical simulations of grassland fires were carried out through fuel-breaks with uniform and random fuel reduction, in order to determine (1) the threshold value of fuel-reduction percentage that would stop an incoming steady surface fire and (2) the distance that the fire will cross within the fuel-break before extinction. Two methods were used for fuel reduction: homogeneous reduction of fuel packing ratio and random reduction of fuel coverage. The threshold value of fuel-reduction percentage and the fuel-break width would naturally depend on the wind speed and on the fuel properties (fuel load, moisture content, …) that determine the rate of spread (ROS) and fire intensity before the fuel-break, as well as the fire regime. The simulations were conducted using FireStar3D - a fully physical, multiphase, CFD fire simulator. The final objective of this project is to relate the threshold value of fuel-reduction percentage that marks the fire go/no-go transition and the fuel-break width to the fire parameters.