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Computing the Effect of Sprinkler Sprays on Fire Induced Gas Flow.

pdf icon Computing the Effect of Sprinkler Sprays on Fire Induced Gas Flow. (609 K)
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.