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This article presents a theoretical work on liquid heat-up in the case of a pool fire. It is assumed that the convective currents occurring within the upper layer of the liquid are induced by Rayleigh–Bénard instabilities that are caused by in-depth radiation. The upper layer depth has been estimated based on the analytical solution of a one-dimensional Fourier’s equation for the temperature with a source term for in-depth radiation. The model has been assessed against experimental data for a 9-cm-diameter methanol steady-state pool fire and three different liquid depths (18, 12 and 6 mm). The general trend, that is, increase in the upper layer depth as the bottom boundary temperature increases, is well captured. In order to ensure that the well-mixed upper layer is at a temperature near the boiling point (as suggested by the experimental data), an improvement is proposed based on a radiative heat balance integral method. In addition to the above, a novel methodology is developed for the calculation of the ‘effective’ thermal conductivity as a means to circumvent detailed calculations of heat transfer within the liquid.

This article presents computational fluid dynamics results of the impact of a water spray on the fire smoke layer inside a hood. The models and the settings of parameters are discussed. Three experiments are performed by means of computational fluid dynamics simulations, and the comparisons show good agreement between measured data and predicted results. The simulation results provide insight into the temperature and flow fields for the configuration at hand, revealing an entrainment effect. The influence of the water spray characteristics on the downward smoke displacement due to drag and cooling is explained. Furthermore, an extensive sensitivity study of the simulation results to input parameters and mesh size is performed. The inner spray angle (related to vertical water flux) and droplet size are shown to be key parameters when simulating downward smoke displacement caused by a spray.

This article presents a large eddy simulation study of a pool fire in a well-confined and mechanically ventilated multi-room configuration. The capabilities of FireFOAM are assessed by comparing the numerical results to a well-documented set of experimental data available from Propagation d’un Incendie pour des Scénarios Multi-locaux Elémentaires. The eddy dissipation concept, finite volume discrete ordinate method, and one k-equation model are used for combustion, thermal radiation, and sub-grid scale closure, respectively. The main boundary conditions are imposed based on the experimental profiles. A detailed comparison is made with available experimental data. Good agreement between the large eddy simulation results and experimental values is achieved for temperatures, velocity, CO2volume concentrations, and pressures for most compartments. There are some noticeable underpredictions of temperature in the outlet room. Overall, FireFOAM is shown to have good predictive capabilities for the present confined large-scale fire scenario.

The proposed method of forecasting a single-room fire growth based on inverse modelling relies upon the assimilation of temperature measurements at the doorway level from floor to soffit height. These measurements are processed in the context of a two-zone model to obtain transient profiles of neutral plane height, XN, and upper layer temperature, Tu. An additional correlation is used to deduce the smoke layer height, h, within the fire room. The obtained profiles of Tu, XNand hover a given period of time (the ‘assimilation window’) are used to estimate the fire growth factor, α, the time delay, t0, and the heat loss factor, λc, with a two-zone inverse modelling procedure. Instantaneous displays of the future fire development are then delivered. Experimental data of four furniture fires in an ISO-room are analysed to illustrate the proposed forecasting methodology, which provides positive lead times between 20 and 235 s, depending on the fire growth rate.

The concept of numerical simulations for real-time Numerical Fire Forecasting is illustrated for the case of natural smoke filling of a large-scale atrium in case of fire. The numerical simulations are performed within the Inverse Zone Modelling framework. The technique consists of assimilating collected data for a certain parameter, in casuthe smoke layer height, into the zone model in order to estimate an unknown of the problem (‘model invariant’), mainly the fire heat release rate. A forecast in terms of evolution of smoke level and temperature can then be produced. Because zone model calculations are very fast, positive lead times of several minutes are obtained. The developed model produces reliable forecasts for the cases considered. Equally important, the robustness of the technique is illustrated: the sensitivity of the results to the ‘initial guess’ of the model invariants is small (i.e. the method converges easily); one model invariant is sufficient to obtain reliable predictions for smoke layer height evolution; the data assimilation window length does not affect the results significantly. The method automatically provides a different value for the plume entrainment constant, depending on the position of the fire (in the middle of the atrium or in a corner).