Wildfire Ember Transport Modeling

Image source: News Tribune; Firebrands from burning tree in 2021 Caldor Fire


This project is about the numerical modeling of firebrand showers in wildfire simulations.


Firebrand shapes

Experimental data has shown that firebrands are made of 3 basic shapes: compact, plate, and rod. Studies have shown that particles of different shapes have different flight trajectories. And in the wildfire research community, these difference have not yet been fully explored.

Image source: NCAR; WRF-Fire: Wildland Fire Modeling

Small & Large-scale Turbulence

Modern wildfire simulations use large grid sizes in their computational meshes (around 250-300 m). This leads to only large-scale turbulence seen in the flow. Understanding the transport of plate and rod shapes in small-scale turbulence is crucial for understanding large-scale transport in wildfire simulations. With this knowledge, researchers will better understand how spot fires are generated.

Turbulent Boundary Layers

Set up


Mesh Resolution

Simulation Cases


Velocity profile validation of turbulent boundary layer simulations with experimental data from Tohidi 2016 and power law fit line.

4% turbulence intensity

7% turbulence intensity

Power spectral density of turbulent boundary layer simulations validated with Kolomorgov -5/3 Spectrum to show a fully developed flow.



Iso-surfaces of the vortices in the 4% turbulence intensity simulation case

Firebrand Transport Simulations

Small-scale Transport

A series of 32 tests were conducted in the high-resolution turbulent boundary layer simulations in uniform and turbulent velocity fields. Plates and rods were released at 4 different heights

Impact and Purpose

Climate change is a major issue in our society today and wildfires are a growing problem across the world. Completing my project will help push our understanding of how wildfires spread, and help create better fire models. And this could help firefighters and emergency personnel stop wildfire spread and save lives.