The computations of buoyant fires and fire suppression

Abstract

This thesis presents a comprehensive computational study of buoyant turbulent diffusion flames and water-based fire suppression, using a novel burner configuration developed at the University of Sydney. The research aims to advance current fire modelling practices by capturing the full progression of fire development from turbulence-enhanced flame formation to suppression dynamics. A key focus is placed on resolving the complex interplay between turbulence, combustion, and suppression effectiveness, particularly under varying injection strategies.

To validate the modelling framework, benchmark simulations of Sandia Flame D were performed using the ReactingFoam solver. The results demonstrated good agreement with experimental data and established the baseline performance of the numerical approach. The study then introduces the USYD Burner, a newly developed platform featuring a recessed perforated plate that enables controlled modulation of fuel-side turbulence without altering heat release rate. Numerical simulations using ANSYS Fluent and FireFOAM were conducted under both laminar and enhanced turbulence conditions, revealing clear changes in flame structure, mixing intensity, and velocity fields.