- Author
- Prasad, K. R. | Li, C. | Kailasanath, K. | Ndubizu, C. | Anath, R. | Tatem, P. A.
- Title
- Numerical Modeling of Fire Suppression Using Water Mist. Part 1. Gaseous Methane-Air Diffusion Flames. NRL Memorandum Report.
- Coporate
- Naval Research Laboratory, Washington, DC
- Sponsor
- Office of Naval Research, Arlington, VA
- Report
- NRL/MR/6410-98-8102, January 19, 1998, 53 p.
- Keywords
- water mist | fire suppression | numerical models | diffusion flames | methane | air | jet flames | droplets | vapor phases | equations | thermodynamics | kinetics | flame suppression | extinction | water supply | fuel flow rate
- Identifiers
- base case diffusion flame results; interaction of water mist with flame; droplet dynamics; comparison of suppressant results to experimental data; effect of droplet diameter, injection density and velocity
- Abstract
- This report is the first in a series dealing with the numerical modeling of fire suppression using water mist. The focus of this report is on the suppression of gas jet diffusion flames using fine water droplets. A two-continuum formulation is used in which the gas phase and the water mist are both described by equations of the eulerian form. The model is used to obtain a detail understanding of the physical processes involved during the interaction of water mist and flames. The relative contribution of various mist suppression mechanisms is studied. The effect of droplet diameter, spray injection density and velocity on water mist entrainment into the flames and flame suppression is quantified. Droplet trajectories are used to identify the regions of the flame where the droplets evaporate and absorb energy. Finally, the model is used to determine the water required for extinction, and this is reported in terms of the ratio of the water supply rate to the fuel flow rate.