UTILIZING A HIGH-RESOLUTION CFD-BASED MODEL TO REPLICATE THE BURNING OF A TWO-STORY STRUCTURE IN THE MAUI WILDFIRE

Abstract

The Wildland-Urban Interface (WUI), the area where structures and other human development meet with undeveloped wildland, grows by millions of acres per year in the United States. The WUI experiences unique challenges when considered in the realm of fire protection engineering, with potential fires in the WUI endangering tens of thousands of communities nationwide. On August 8, 2023, one such fire devastated the historic Lahaina town in Maui, Hawaii, destroying over a thousand structures. This project uses the NIST Fire Dynamics Simulator (FDS) to recreate a part of the fire that destroyed two neighboring residences in Lahaina. Detailed models and configurations are created to replicate wind, vegetative fuel combustion, and structural burning. Results of the simulation show that the use of a half-wall height burner configuration in an optically thin radiation model best recreated the flame spread between adjacent structures and vegetative fuels. Models qualitatively demonstrate flame spread between structures; however, quantitative timing is highly sensitive to uncertainty. Sensitivity analysis suggests that the emissivity of a structure’s outermost layer is the primary source of uncertainty in model results.