QES-Fire: A Dynamically-Coupled Fast-Response Wildfire Model

QES-Fire: A Dynamically-Coupled Fast-Response Wildfire Model

A microscale wildfire model (QES-Fire), which dynamically couples the fire front to microscale winds, was developed utilizing a simplified physics rate of spread (ROS) model, a kinematic plume-rise model and a mass-consistent diagnostic wind solver. The model is 3-D and includes coupling between fire heat fluxes and the wind field. QESFire's ability to represent the strength of convection (e.g., updraft velocity and buoyancy flux) is evaluated by comparing the velocity fields from QES-Fire to the resultant velocity fields from a convective atmospheric large eddy simulation using the Weather Research and Forecasting model (WRF). QES-Fire has less than a 7% relative difference in the centerline vertical velocity, and less than a 10% relative difference in the integrated buoyancy flux from those calculated by WRF at a speed 8800 times faster per computational core than WRF. Additionally, the model is compared to ROS and tower data from the FireFlux II field experiment, with less than a 10% relative difference in the ROS.