The technical objective of this research is to develop an advanced modeling and simulation framework for predicting the suppression of large-scale fires using water mists and sprays. The modeling is based on Large Eddy Simulation (LES) techniques using probabilistic based sub-grid scale (SGS) models to account for multiphase coupling of buoyancy-driven turbulence, combustion, suppression thermochemistry, droplet transport, and thermal radiation heat transfer. Specifically, this effort is focused on: (1) improved SGS turbulence models for buoyancy-driven flows, (2) new SGS stochastic process descriptions to account for turbulence-chemistry-radiation-particle interactions, and (3) radiation heat transfer in turbulent multiphase flows. The implementation of these models also includes development of advanced numerical algorithms for efficient implementation of Monte Carlo solution procedures implemented on massively parallel computers and development of gridless radiation methodologies for participating anisotropic scattering media. This combined set of new models and algorithms should result in a significant improvements in fire-suppression field modeling as well as advance the quantitative treatment of other applications in which multiphase combustion and radiation processes are important.
The significance of this effort is to offer scientific insight on suppressing large-scale fires that have recently caught the attention of our nation, ranging from the destruction of the twin towers in New York City to the wild fires that have raged through the southwest. One of the challenges in controlling these fires is predicting the performance of the water-delivery system, which depends on the understanding of dynamics of flame suppression processes in highly turbulent, strongly radiating, multiphase, reacting flows. One of the goals of this research is to provide a high fidelity predictive tool to simulate these processes. Such a tool will allow fire-protection engineers to design better fire-suppression systems to insure fire safety for our nations' critical infrastructures.
