Evaluation of a zone-based model for commodity classification using a representative fuel

Abstract

This study presents the development of a zone-based model for commodity classification. The model divides the rack storage into multiple zones with each representing one tier of commodity. The fire spread within each zone is modeled using energy conservation for burning surface area. The water transport between zones is modeled using mass conservation. Effective properties are used to simplify the commodity behavior for fire spread and suppression. Model parameters are estimated or optimized based on experimental data. The model performance is evaluated against a representative commodity with well-established flammability properties. The chemical heat release rate matches generally well with experimental data under different storage heights and water application conditions. The model is able to predict the values of Critical Delivered Flux (CDF) for higher-tier storage based on two lower-tier experiments. The predicted CDF values reasonably agree with the experimental results. This work demonstrates a means to generalize results from tests under controlled water application conditions, which is critical to improve the cost-effectiveness of commodity classification.