Comparison of combustion models based on fast chemistry assumption in large eddy simulation of pool fire

Abstract

In the present study, OpenFOAM software was adopted to implement a solver using the Steady Laminar Flamelet Model (SLFM) and Eddy Dissipation Concept (EDC) combustion models. Afterward, the compatibility of fast chemistry-based combustion models consisting of the Infinitely Fast Chemistry, Eddy Dissipation Model (EDM), EDC, and SLFM combustion models was studied in the simulation of 2.7 MW methane pool fire, by employing a one-equation sub-grid-scale turbulence model. Comparing the results against experimental data indicates that the SLFM model anticipates more flame width, and it is capable of predicting the mean turbulent kinetic energy with the maximum error of 4-8%. On the other hand, the EDM model can attain the mean vertical velocity of the flow in the range of 5-10% which is more accurate than the other models. Furthermore, the puffing frequency was derived by the Fast Fourier Transform analysis of vertical velocity, pressure, and temperature in a given time for each of these models. EDM and EDC combustion models illustrated a relative error of 7%, in predicting puffing frequency, compared to experimental results. Keywords LES • Large-scale pool fire • Fast chemistry combustion models • Flamelet model Abbreviations EBU Eddy breakup model EDC Eddy dissipation concept EDM Eddy dissipation model FDS Fire dynamic simulator FFT Fast Fourier transform HHR Heat release rate IFC Infinitely fast chemistry LES Large eddy simulation PDF Probability density function PIV Particle image velocimetry SGS Sub-grid scale SLFM Steady laminar flamelet model VHS Volumetric heat source ∞ Ambient density (kg∕m 3) Scalar dissipation rate (s −1

A Study on turbulence-combustion interaction and Sub-grid Scale model in the simulation of Methane pool fire using LES

“…A review of the results shows that although the coefficients of the combustion model reduced, the accuracy of the numerical results is closer to the experimental results; however, the use of other combustion models also can improve the numerical results. For example, the use of a steady laminar flamelet model (SLFM) or flamelet generated model (FGM) is one of these models [3].…”

The importance of compatible sub-grid scale and spatial discretization models on the simulation of large-scale pool fire

“…detail is given in [1]). In selecting the grids, it was attempted to choose the domain A grids in such a way that the mesh resolution was the same as domain B's grids.…”

“…The impact of each of these parameters has been investigated in various studies. For example, the influence of combustion model and reaction kinetics has been investigated by Razeghi et al [1]. The turbulence model and discretization methods affect the accuracy of the simulation, like other parameters.…”