- Author
- Baum, H. R. | McGrattan, K. B.
- Title
- Simulation Enclosure Fire Dynamics and Suppression.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Book or Conf
- Science, Technology and Standards for Fire Suppression Systems. National Research Institute of Fire and Disaster (NRIFD) Symposium, 2nd Proceedings. July 17-19, 2002, Tokyo, Japan, 217-233 p., 2002
- Keywords
- fire suppression | water mist | enclosures | computer simulation | water sprays | fire models | sprinklers | sprinkler activation | sprinkler sprays | water droplets | heat transfer | mass transfer | pallet storage | computational fluid dynamics
- Identifiers
- Large-Eddy Simulation (LES); water delivery
- Abstract
- At least three different physics based approaches to fire dynamics simulations have evolved over the years; lumped parameter or ``zone models'', computational fluid dynamics models based on classical turbulence modeling techniques, and large eddy simulations. Large eddy simulations provide the most realistic description of fire phenomena developed to date. All such simulations provide descriptions of the processes that control the mixing and combustion of fuel and air at elevated temperatures. In an enclosure fire these processes are complicated by the fact that the fuel was initially part of the building or its furnishings, and the air supply is controlled by the interaction of the fire with its surroundings. The geometry of the building and its furnishings all influence the fire and are in turn changed by it. Numerical models of fire suppression are dependent on the level of detail given to the combustion and fuel pyrolysis processes. Present models of gas phase suppression limited by the use of highly simpified models of combsution mechanisms in large-scale simulations. Models of solid phase suppression are limited by the lack of well-accepted, robust pyrolysis models that have enough physical detail to accomodate the inclusion of water impingement. Several lumped parameter models of solid phase suppression by water have been developed over the past decade, but these models do not neccesarily work well within a computational fluid dynamics framework. The key to improving models of both fire dynamics and suppression phenomena is the interface between the gas and solid phases. More physics is needed to properly describe solid phase suppression dynamics, and existing fundamental combustion models of gas phase suppression need to be simplified so that both parts of the suppression problem can be brought into the same conceptual framework.