Consequence analysis of heptane multiple pool fire in a dike

Abstract

Multiple Pool Fire (MPF) reasonably enhances the flame height, the rate of fuel combustion and irradiation due to cascading effect and flame merging of multiple pools. The distribution of temperature and radiative heat flux from the source is the key parameter in predicting safety distance. The current study’s major objective is to develop a Computational Fluid Dynamics (CFD) model to calculate the safety distance of MPF and validate the predicted results (flame temperature, radiative heat flux, CO2 and O2 mass fraction) with the experimental data. The flame structure and its thermal properties have been evaluated using the Reynolds Averaged Navier Stokes (RANS) and the Large Eddy Simulation (LES) model. The CFD results are found to be in close agreement with the experimental findings. The LES turbulence model predicts more accurately the flame structures and the fluctuations with an error of less than 3%, while the Re-Normalization Group k-ε model predicts the average characteristics. This authenticates the accuracy of computational methodology and robustness of the LES turbulence model to predict MPF flame characteristics. Furthermore, this computational methodology can be utilised by the industries for quantitative risk assessment and the worst-case scenario of various pool fires to save the human and material of the workplace beforehand.

Numerical prediction of fire dynamics and the safety zone in large‐scale multiple pool fire in a dike using flamelet model

“…The CFD modelling of pool fires has been carried out using two different approaches including flamelet generated manifold (FGM) [34][35][36] and species transport model. [23,[27][28][29][37][38][39] The flamelet-based modelling approach considers the detailed reaction chemistry with all intermediate reactions, including all reaction kinetics and transport properties in the form of probability density function (PDF) tables. [34,40] It gives a very clear representation of flame structure and details of fluctuations.…”

“…[34,40] The reacting species transport approach involves solving the transport equations for all the chemical species present in the detailed combustion mechanism. [7,39,41] As a result, the number of equations to be solved with the reacting species transport approach grow and become computationally intensive. CFD modelling of small-scale (less than 1 m size) pool fire have been carried out for single [7,36,37,42] and multiple pools.…”

“…[6,27,28,43] Large-scale pool fire CFD modelling has also been reported. [35,39,44,45] The effect of radiation is captured by using P1 [27,28] and the discrete ordinate [32] radiation model. Turbulence modelling is crucial for the prediction of the turbulent structure of a pool fire.…”