CFD and engineering method coupling for evaluating the fire relative to battery transportation

Abstract : Using CFD fire modelling for underground infrastructure always face off the same problem that consists in defining the heat release rate and toxic gas source term. Based on a large series of experiments, standards were defined some decades ago and are currently used for safety design. The development of new energy carriers however let fire safety engineer to wonder about the applicability of those standards and the possibility to consider more realistic curves. This paper proposes an innovative model to build the heat release rate and toxic gas emissions curve for trucks. It consists in splitting the vehicle in several interconnected elements that have their own curves. A relation can then be supposed for the propagation in order to obtain a global curve. After comparison to experimental available data, this model can be applied for designing source term including new energy carriers as batteries. One of the main interest of such an approach consists in considering individual fire tests that could be easily managed and then considering real emission factors for the different individual component of the vehicle. Finally, the fire and toxic gas emission curve produced by such an approach can be introduce in a CFD code, not for safety design because of the specificity of the curve but for giving a positioning regarding the applicability of standards compared to current real fires.