Local to continental scale coupled fire-atmosphere simulation of large industrial fire plume

Abstract

This paper presents an approach to model the multiscale smoke dispersion following industrial fires, based on the atmospheric code Meso-NH coupled with the ForeFire surface fire code. Meso-NH can solve explicitly micro to meso-scale meteorology, while ForeFire allows for an efficient parametrization of the injected heat and vapour fluxes. The combination of these two models allows for a straightforward implementation of the heat source term and simultaneously accounts for its effect on local meteorology (as convection and latent heat), thus leading to a prognostic representation of the developing plume. In addition to its multiscale reach, the main contribution of the proposed approach is the explicit modelling of the effects of released heat and vapour on the local meteorological conditions which determine the height and the near-to-far scale development of the rising fireplume. The context of the study imposed to set model parameters that allow for faster than real time forecast along with a qualitatively realistic representation of the plume. Quantitative assessments on the physio-chemical properties of the plume require finer physical models which are available at the expense of an increased computational time and require quantitative estimates of the chemicals involved in the combustion, and are let to future developments. Model evaluation in the proximity of the fire is performed by comparing results with a combustion CFD solver on an idealized situation, followed by a mesh sensitivity study. Then, the proposed coupled method is applied to a real-case multi-scale simulation of smoke dispersion from the local (city) to the continental scale, with a twice faster than real-time computation time.