Effects of combustion model in predicting pool fire and fire plum behaviors using a large eddy simulation method

In this paper, methane pool fire and fire plumes with two heat release rates of 14 and 45 kW are simulated using Large-Eddy Simulation (LES) method. In order to investigate the accuracy of various combustion models, two combustion models of Eddy Dissipation Model (EDM) and Infinity Fast Chemistry (IFC) have been evaluated with a one-equation sub-grid scale model. The simulated results are in a good agreement with experimental measurements, and show the scaling relations of mean temperature and velocity in each pool fire region including stable flame, intermittent and plume. Results indicate that, EDM combustion model have a better prediction of mean velocity and temperature while it have more computational time. In addition, by incorporating Fast Fourier Transform (FFT) analysis on the transient results of temperature and velocity, the prevailing frequency for the temperature and velocity is equal which is 2.75 Hz for the current case. Moreover, energy cascade of eddies shows the accuracy of the LES in predicting pool fire dynamic.