Determination of Material Property Input Data for Fire Modeling

As submitted by the proposer: The proposed effort will provide experimental methods and detailed procedures for generating thermal, physical, and combustion property data for solid material pyrolysis models for use in predicting response in fire dynamics models. This proposal will address the need in the forensic discipline of Fire and Arson Investigation for more adequate materials property data inputs for accurate computer fire models. Computational models currently exist to predict the details of material pyrolysis, but there are numerous input data required to conduct these analyses. This research proposes developing an accurate set of material properties for pyrolysis modeling through a combination of properties measured directly in experiments and properties collectively determined through optimization. It is hypothesized that more realistic (and hence more accurate) properties can be achieved through limiting the number of properties determined through optimization techniques based on well-designed experiments. The decision on which properties to measure versus determine through optimization will be based on the sensitivity of the model to the property as well as ease of experimental determination of properties. The research will perform model sensitivity analysis on three different types of pyrolysis models that have a range of sophistication to identify the level of accuracy each property needs to be quantified. Based on the difficulty and time required to measure properties as well as the accuracy at which properties must be measured, a methodology will be developed that identifies which properties should be measured versus determined through optimization. For properties determined through optimization, tests will be designed in this research to accurately determined properties through limiting the physics that are occurring in the experiments. This new methodology will be used to determine properties on eight different materials. The property determination methodology developed in this research will be used to quantify properties for eight different materials with the goal of generating the properties for a single material with three man days of labor. The capability of the three levels of pyrolysis models to predict material response using properties from the new methodology developed in this study will be evaluated through comparison of model results to validation experiments that are different than those used to develop properties. These validation experiments will be conducted on each of the eight materials considered in this study to demonstrate the general applicability of the approach. The research will produce a methodology that practitioners can follow to determine material properties for use in their material pyrolysis models as well as a benchmark data set for future reference. It is expected that this research will not only provide a more standardized approach for material property determination for forensic applications but also for the general fire protection engineering community. Note: This project contains a research and/or development component, as defined in applicable law. ca/ncf