One-dimensional pyrolysis of carbon based composite materials using FireFOAM

Publication date: April 2018
Source:Fire Safety Journal, Volume 97
Author(s): N. Grange, K. Chetehouna, N. Gascoin, A. Coppalle, I. Reynaud, S. Senave
Composite materials used for aerospace applications are vulnerable when exposed to high temperatures and may generate toxic fumes and particles when submitted to fire stress. This hazard is strictly framed by aviation regulations. Thus, research on composite behavior under fire now aims to develop reliable physical models to be implemented into Computational Fluid Dynamics (CFD) codes in order to meet this challenge and better understand the physics of fire growth and materials flammability. The initial chemical reactions (pyrolysis and ignition) should be evaluated first and then validated against experimental data at the mesoscale. A cone calorimeter provides realistic degradation conditions and a large heat flux range (from 30 to 120 kW/m²), making it a good tool for validation. In this study, the FireFOAM CFD solver was used to predict the one dimensional pyrolysis of the condensed phase of two carbon-reinforced composite materials, a thermosetting phenolic resin and the thermoplastic Poly (Ether-Ketone-Ketone) (PEKK). The numerical results were compared to cone calorimeter experiments at the mesoscale, and provided a good prediction of the mass loss and heat release rate for the materials considered. A maximum relative error of 5% was found between experiments and numerical simulation of the mass loss for the carbon-PEKK and the carbon-phenolic composites. Moreover, the numerical heat release rate presented a good reproduction of both peak intensity and time. A sensitivity analysis was performed to evaluate the reaction of the model to the variation in different parameters, and highlighted the strong influence of the material density when considering the thermophysical properties and activation energy for the kinetic parameter.



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