Computing the Effect of Sprinkler Sprays on Fire Induced Gas Flow.
Computing the Effect of Sprinkler Sprays on Fire Induced
Forney, G. P.; McGrattan, K. B.
National Institute of Standards and Technology (NIST)
and Society of Fire Protection Engineers (SFPE).
International Conference on Fire Research and
Engineering (ICFRE). Proceedings. September 10-15,
1995, Orlando, FL, SFPE, Boston, MA, Lund, D. P.;
Angell, E. A., Editor(s)(s), 59-64 pp, 1995.
fire research; sprinkler response; gas flow; curtain
walls; fire simulation; fluid flow; smoke detection
Over the last twenty years there has been much debate
concerning the interaction of sprinklers and draft
curtains in large storage facilities. At issue is
whether or not the two fire protection systems are
mutually beneficial. It has been suggested that in the
event of a fire the draft curtains inhibit the spread of
hot gases near the ceiling, delaying the activation of
sprinklers needed to suppress the fire. There has been
a call for large scale tests to quantify this scenario.
In support of such test being planned at NIST, an effort
underway to numerically simulate the interaction of
sprinklers and draft curtains in the presence of a fire
in a large enclosure, such as a warehouse. For this
project, the intent is not to necessarily simulate in
detail the two phase interaction of droplets and air
from a single sprinkler, nor to predict the suppression
of the fire itself, but rather to study the effect of
dozens of sprinklers on a fire-driven flow field in
enclosures up to 60 meters on a side and 10 meters high.
The sprinkler spray serves to cool the upper layer hot
gases by both mechanical mixing with cooler gases below
and absorption of heat by the droplets. Approximations
to the governing Navier-Stokes equations make
calculations with over one million cells possible with
run times on the order of 24 hours.