##
Flame Suppression Effectiveness.

Flame Suppression Effectiveness.
(5174 K)

Hamins, A.; Gmurczyk, G. W.; Grosshandler, W. L.;
Rehwoldt, R. G.; Vazquez, I.; Cleary, T. G.; Presser,
C.; Seshadri, K.

NIST SP 861; April 1994.

Evaluation of Alternative In-Flight Fire Suppressants
for Full-Scale Testing in Simulated Aircraft Engine
Nacelles and Dry Bays. Section 4, Grosshandler, W. L.;
Gann, R. G.; Pitts, W. M., Editor(s)(s), 345-465 pp,
1994.

### Available from:

Government Printing Office

Order number: SN003-003-03268-9

### Keywords:

halons; fire suppression; effectiveness; diffusion
flames; turbulent flames; premixed flames; detonation;
chain reactions

### Abstract:

*
A flame will be extinguished when the time required for
the chain reaction which sustains combustion exceeds the
time it takes to replenish the necessary heat and
reactants. A characteristic time for reaction can be
estimated from the inverse of a global kinetic rate
coefficient expressed in Arrhenius form as [equation]
where B is a molecular collision frequency factor, Eo is
a global activation energy, R is the ideal gas constant,
and T is the gas temperature. Assuming reactant species
and heat are transported at about the same rate (i.e.,
unity Lewis number), a characteristic time for
replenishing both can be estimated from a convective
flow velocity and a length scale by [equation].
*