Semi-empirical Model for Fire Spread in Shrubs with Spatially-Defined Fuel Elements and Flames

A semi-empirical model was developed which forms shrub geometries from distinct fuel elements (e.g. leaves) and describes flame spread from element to element. Ignition, flame growth and flame decay patterns were based on combustion data of single leaves. Extension of the model to various heating conditions was achieved by scaling the flame growth parameters using physics-based heat transfer models. The resulting model offers a novel approach to examine fire spread and to explicitly describe both distinct fuel elements and fire behavior. This approach balances computational speed and modeling detail while providing a unique perspective into fire spread phenomena. Comparisons of the tuned model to fire spread behavior measured in an open-roofed wind tunnel benchmarked the model’s ability to simulate fire spread in manzanita shrubs.