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Computer Simulation of the Liquid Agent Spray Motion and Evaporation.

Computer Simulation of the Liquid Agent Spray Motion and
Evaporation.
(389 K)

Gmurczyk, G. W.; Cooper, L. Y.; Grosshandler, W. L.;
Pitts, W. M.

Paper XIII-3;

Institute for Liquid Atomization and Spary Systems
(ILASS-Europe) and CORIA. Liquid Atomization and Spray
Systems, 6th International Conference Proceedings.
ICLASS 94. July 18-22, 1994, Rouen, France, Begell
House, Inc., NY, Yule, A. J.; Dumouchel, C.,
Editor(s)(s), 1039-1046 pp, 1994.

### Keywords:

sprays; evaporation; computer simulation; fire
extinguishing agents; halon 1301; mathematical models;
equations; gravitational fields

### Abstract:

*
The discharge of a liquid fire extinguishing agent
stored in a pressurized vessel through an orifice
generates a freely moving spray outside the vessel. The
flow has been modeled as a two-phase, three-component,
turbulent, compressible, dissipative flow. It has been
assumed that the gaseous phase consists of agent vapor,
nitrogen and oxygen, whereas the liquid consists of
agent only. Viscosity, heat conduction, mass diffusion
and turbulence have been included in the description.
Interphase processes; such as Stokes forces and
aerodynamic drag, forced convection and evaporation;
have also been included. The spray is assumed to be a
monodispersed phase described by the Sauter mean
diameter. All the transport coefficients, the specific
heats and the vapor pressure equation are temperature
dependant. The impact of the gravitational field on the
momentum exchange has also been included. The
mathematical model describing the physical phenomena has
been formulated with the use of the partial differential
equations associated with the relevant initial-boundary
conditions, expressing the balances of mass, momentum
and energy. The set of time-dependant equations has
been referred to the two-dimensional cylindrical
geometry. The equations have been solved numerically
with the use of time-marching finite-difference
partially implicit scheme. The Conchas-Spray computer
code of Los Alamos National Laboratory has been used to
run the calculations. Sample results obtained for an
extinguishing agent have been presented and the
potential of the model and computer code have been
discussed.
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