Chapters authored
Numerical Study on the Outdoor Wind Effects on Movement Smoke along a Corridor
In this chapter, a numerical investigation is presented in order to highlight the effects of outdoor wind on smoke movements along a corridor in a compartment. For this, the Computational Fluid Dynamics (CFD) code, fire dynamics simulator (FDS), was used to model the reactive flows in interaction with outdoor wind. The wind velocity is taken between 0 and 12.12 m/s, based on the experimental result data come from the work of Li et al. was performed. From numerical data, it was found that smoke stratification state in the corridor depends on Froude number (Fr) and it can be divided into three cases: stable buoyant stratification (Fr < 0.38), unstable buoyant stratification (0.38 ≤ Fr < 0.76), and failed stratification (Fr ≥ 0.76). When Fr ≥ 0.76, smoke stratification is completely disturbed and smoke occupies the entire volume of the compartment, highlighting a risk of toxicity to people. Indeed, it was observed that the velocity of the outdoor wind influences strongly the concentration of O2, CO2, CO, and visibility in the corridor and smoke exhaust. Moreover, for the input data used in the numerical modelling, the global sensitivity analysis demonstrated that the main parameters affecting the smoke temperature near the ceiling are the mass flux of fuel and the activation energy.
Part of the book: Fire Safety and Management Awareness
BLEVE Fireball Effects in a Gas Industry: A Numerical Modeling Applied to the Case of an Algeria Gas Industry
This chapter presents the numerical modeling of the BLEVE (Boiling Liquid Expanding Vapor Explosion) thermal effects. The goal is to highlight the possibility to use numerical data in order to estimate the potential damage that would be caused by the BLEVE, based on quantitative risk analysis (QRA). The numerical modeling is carried out using the computational fluid dynamics (CFD) code Fire Dynamics Simulator (FDS) version 6. The BLEVE is defined as a fireball, and in this work, its source is modeled as a vertical release of hot fuel in a short time. Moreover, the fireball dynamics is based on a single-step combustion using an eddy dissipation concept (EDC) model coupled with the default large eddy simulation (LES) turbulence model. Fireball characteristics (diameter, height, heat flux and lifetime) issued from a large-scale experiment are used to demonstrate the ability of FDS to simulate the various steps of the BLEVE phenomenon from ignition up to total burnout. A comparison between BAM (Bundesanstalt für Materialforschung und –prüfung, Allemagne) experiment data and predictions highlights the ability of FDS to model BLEVE effects. From this, a numerical study of the thermal effects of BLEVE in the largest gas field in Algeria was carried out.
Part of the book: Fire Safety and Management Awareness