Numerical simulation of plume-dominated shrubland-fire spread: a parametric study
Abdel-Razzak Tayba, Charbel Farhat, Charbel Karam, Gilbert AccaryBackground
Understanding wildfire behavior is essential for fire-spread prediction.
Aims
In a previous study, wind-driven shrubland fires were investigated, with prevailing wind controlling fire spread. The present work focuses on the contrasting plume-dominated regime, in which buoyancy governs fire dynamics, to understand how the rate of spread (ROS) and other fire properties relate to Byram’s convective number in this case.
Methods
A parametric analysis including 108 simulations was carried out using wildfire model FireStar3D, covering different wind speeds and fuel properties.
Key results
A consistent scaling was found between the normalized ROS and Byram’s number, in line with experimental data. Results show that Byram’s number accounts for wind, fuel moisture and fuel height, while fuel volume-fraction has a separate effect on the ROS. The thermal-plume angle scales exclusively with Byram’s number. The fire-establishment phase was also examined, showing a slightly slower spread than under steady conditions, with its duration mainly depending on Byram’s number.
Conclusions
The results clarify how the properties of plume-dominated fires link to Byram’s convective number and emphasize the effect of fuel properties on fire behavior.
Implications
These findings contribute to improved understanding of wildfire dynamics and support the development of prediction tools.