Experimental and numerical investigations in order to model the fire development and propagation for fire safety engineering studie

Fire safety engineering plays an important role in achieving safety objectives in a building and is in way of generalization in all the countries of the world, especially for reaction to fire. It is based on the use of numerical models. However, numerical simulations used for this particular field has got some limitations, for example due to the size of the domains to simulate, the very large number and the complexity of the materials involved, the multitude of the geometric configurations... that do not allow the representation of all the processes. In consequence, reaction to fire cannot be treated accurately in engineering studies and flame ignition or propagation cannot be represented due to the time of calculation. Nevertheless, their description is of first order. In this context, this work gives a first approach on technical bases in order to represent ignition, fire growing and development and flame propagation in engineering study. This description requires an understanding of the different processes involved in both solid and gaseous phases as well as their interface. A means to represent small-scale phenomena with engineering model limitations (time to compute, size meshing) should be performed.
For this, a multiscale study both experimental and numerical is in progress on two types of polymers: a pine wood and PVC. This approach is conducted in order to identify relevant phenomena that drive fire growing and flame propagation for different configurations: vertical, horizontal, co-current and counter-current. The study should lead to the definition of new sub-models, of numerical model recommendations (size meshing, wall laws, etc.) in order to describe those phenomena at large scales without too large time consumption.