Abstract

CFD simulations are used increasingly in fire safety studies to evaluate the possibility of keeping a teanble atmosphere when evacuating a room in the event of a fire. Such simulations are subject to uncertainties arising from simplifications inherent in the modelling, and uncertainties in the parameters to be used for the calculations. These uncertainties can have a major impact on the results of the simulations, and can lead to erroneous conclusions, so it is vital to be able to assess the impact of uncertainties on the results of CFD simulations performed for fire safety studies. We propose to evaluate the influence of parameters (initial conditions, simulation parameters) on the result using small variations around a reference case (so-called local analysis). We also show how a non-local analysis of the influence of an implicit parameter can be performed. This technique enables the identification of key parameters for which a small error in the estimation of their values may cause large variations of the results. Such parameters require a more detailed study, to reduce the consequences of the uncertainty in their value.