Simulation of the Dynamics of a Wind-Driven Fire in a Ranch-Style House - Texas

This report describes the results of calculations using the NIST Fire Dynamics Simulator (FDS) performed to provide insight on the thermal conditions that may have occurred during a wind-driven fire in a one-story ranch house on April 12, 2009 in Houston, Texas. The FDS simulations represented the building geometry, material thermal properties, and fire behavior based on information gathered from multiple sources. The simulation results are provided in this report. The FDS simulation that best represents the witnessed fire conditions indicate that fire spread throughout the attic and first floor developed a wind-driven flow with temperatures in excess of 260 °C (500 °F) between the den and front door. The critical event in this fire was the creation of a wind-driven flow path between a large span of failed windows on the upwind side of the structure, and the open front door on the downwind side of the structure. Floor-to-ceiling temperatures rapidly increased in the flow path, in which members were performing interior operations. In a simulation without wind, the flow path was not created after the large span of windows failed, and the thermal environment surrounding the location of interior operations improved.