Comparing qualitative damage assessments to FDS predicted heat distribution: A proposed methodology for forensic fire origin determination

The fire investigation industry has been increasingly called upon to create, update, and validate systematic methodologies for testing and developing area of origin hypotheses. To date, the research has focused on methods to test or determine a particular area of origin within a single compartment. However, the modern fire investigator often finds themselves in situations in which multiple compartments within a structure have endured significant damage due to post-flashover burning schemes, which makes the determination of the compartment of origin a difficult endeavor. Often, fire investigators have utilized computational fluid dynamics (CFD) software such as the Fire Dynamics Simulator (FDS) to assist in evaluating fire effects and behavior in such complex scenarios. While several large-scale multi-compartment fire investigations have utilized FDS to test or develop a compartment of fire origin hypothesis, no general methodologies have been proposed for such an investigation. This research seeks to build upon previous research and methodologies applicable to a single compartment and develop and validate a methodology for the utilization of FDS to create a data matrix that can be utilized to test or determine a compartment of origin hypothesis in a post-flashover environment. A prescribed qualitative methodology is utilized to synthesize macro scale fire effects and damage distributions, witness statements, and ventilation variations. Multiple FDS simulations were run and the data matrixed for comparison to the scene assessment.