Computational Fluid Dynamics (CFD) Method for Determining the Consequences of Releases Inside a Building

摘要

Computational fluid dynamics (CFD) methods have typically been used for modeling the behavior of instantaneous releases of flammable materials and predicting the resulting impact of potential explosions. In most cases, the actual behavior of a jet of hazardous material upon release, initial air entrainment because of high velocities, and the downwind dispersion, are not generally considered. It is conservative to start with a stoichiometric mixture of a flammable material and air. However, inside buildings where there is a lot of congestion and confinement, such assumptions lead to predictions of extremely high overpressures. These predictions could further lead to expensive decisions for building reinforcements and structural upgrades. By analyzing the behavior of leaks as they may occur, and addressing the dispersion of the plume, accounting for vapor detection systems and emergency ventilation in the room, a much more realistic estimate of impact can be obtained. These realistic estimates of consequences, along with information about the likelihood of releases, are very useful in driving risk-based decisions. This paper will present results of a consequence analysis study related to releases of a highly flammable material inside a room for predicting the actual concentrations, and overpressures at a variety of critical monitor points.