Publications Details

Contaminant entrainment from a gasoline pool fire

Brown, Alexander B.; Zepper, Ethan; Laros, James H.; Restrepo, Louis

Aerosol release in the range of less than 10 μm is of concern in transportation accident situations, particularly those involving radioactive contaminants and fuel fires. An accurate approximation of the Airborne Release Fraction (ARF) is important to properly estimate the impact of the contaminant release to the environment and surrounding population. An experiment was selected which studied contaminant entrainment in a fire and contained enough data sufficiently well presented to simulate with existing computational fluid dynamics (CFD) tools. Work was enabled by utilizing source terms for similar physical systems as presented in other publications. It is possible to investigate physical sensitivities from this model, giving insight into the experimental behavior, and physical processes. The effort also helps prioritize model development in the interest in furthering this predictive capability. Four mechanisms were identified as contributing to contaminant entrainment. Two of these mechanisms, entrainment due to evaporation induction and boiling atomization, were the focus of this study. Parameters, including boiling regime duration, evaporation regime particle size and turbulence, were varied because of their numeric uncertainty, while others like particle injection location, simulation time, and fuel height were varied based on a presumed importance. Entrainment values, as collected downstream of a release, are dependent on the magnitude of the entrainment mechanism, in which boiling far exceeded evaporation in quantity of entrained mass.