Numerical Simulations of a Mechanically-Ventilated Multi- Compartment Fire

The objective of this work was to evaluate the capabilities of a widely used Computational Fluid Dynamics (CFD) code in the fire community, namely the Fire Dynamics Simulator (FDS 5.5.3), in the simulation of a large-scale, well-confined and mechanically ventilated multi-room fire scenario. The CFD analysis focuses on the effect of pressure build-up induced by the fire on the ventilation network. The measured heat release rate (HRR) was therefore prescribed as input in the simulations. Computational results were compared to measurements obtained for one of several experimental scenarios performed at the French Institut de Radioprotection et de Surete Nucleaire (IRSN). The overall trend was well reproduced by FDS. Quantitative comparisons for respectively the total relative pressure, ventilation flow rates and gas temperature (in the fire room) at the steady-state combustion regime have shown underestimations of 18 to 22 %.