Numerical analysis of the characteristics of the decomposition zone of a burning wood sample under cone calorimeter and evaluation of the limiting process

摘要

In buildings, wood material is increasingly used as a construction product or as coatings. Nowadays, fire safety objectives are defined by two approaches, called prescriptive and performance-based design approach. The second approach corresponds to the fire safety engineering, using modelling. However, these models must be designed regard to the simulated case, in order to have results close to reality and to optimize the computing time as well as possible. For example, it is not necessarily useful to have a detailed pyrolysis model if the heating conditions of the material are extremely fast, this would be time consuming and could introduce prediction errors since the model of pyrolysis would call on more input data, and therefore more uncertainty in these data. Therefore, the choice of numerical models requires understanding of wood burning behaviour. In this context, this paper investigates experimentally and numerically the burning of wood through the pyrolysis zone in order to characterize deeply the solid phenomena and to better predict them. A multi-scale approach has been developed using TGA and cone calorimeter tests for the experimental part and Fire Dynamics Simulator for the numerical part.