Fire scene investigation of an arson fire incident using computational fluid dynamics based fire simulation

Fire simulation utilizing computational fluid dynamics (CFD) techniques was employed to reconstruct the aged-care facility fire incident that occurred in Quakers Hill, Sydney, in Nov 2011. Based on the sentence descriptions by the suspect and witnesses, the fire was intentionally lit on hospital beds sheets in an empty room and eventually spread to the entire building. The main objective of this simulation is to determine the fire origin and to gain insights into the fire development that resulted in three fatalities in the burn room. Preliminary numerical studies were initially performed in the model to investigate possible locations of the fire sources before the mock-up experiment was carried out in an actual size test room facility. The measured and predicted gas temperature from the thermocouple readings compared well, particularly with the peak temperature reaching approximately 900°C. Numerical simulation indicated that fire spread within the room was quickly established due to large amount of combustible materials being present and ample entrainment of air from the surroundings into the room through the window and doorway. This article illustrates the promising application of CFD for building fire modelling and simulation to provide evidences of criminal identification for fire investigation.