Experimental and Numerical investigations of the flow characteristics in confined fires

Abstract

Fire compartments are of major concern since they are responsible for fatal accidents. The decision and response times of rescue teams are mainly based on human decisions which result from empirical approaches. Since compartment fires are multi-physical and multi-scale problems, a perfect knowledge of the situation is impossible. A fundamental approach of fire compartments which involves fluid mechanics is of great interest. One of the main issues concerns the transition from located to generalized fire. The most important vehicle leading to generalized fires results in smoke transport. Indeed, temperatures are very high and many species are mixed. In this study, an experimental facility composed of a maritime container is set-up. In parallel, numerical simulations-Fire Dynamics Simulator (FDS) software-based on a LES approach, are used. This dual approach makes it possible to validate the FDS code in ventilated and under-ventilated conditions, considering both the temperature fields and the flow dynamics. The compartment fire allows power up to 1MW. Temperature fields are measured with thermocouples racks, and velocity fields are obtained by large scale Particle Image Velocimetry (PIV). The objectives of the paper are: I) compare and analyze temperature fields from both experimental and numerical data, II) introduce preliminary results on large scale PIV measurements located at the smoke exit. Data are also compared with simulations and III) check the numerical assumptions.