Developing Detector Siting Rules From Computational Experiments in Spaces With Complex Geometries.
Developing Detector Siting Rules From Computational
Experiments in Spaces With Complex Geometries.
Davis, W. D.; Forney, G. P.; Bukowski, R. W.
University of Duisburg. International Conference on
Automatic Fire Detection "AUBE '95", 10th. April 4-6,
1995, Duisburg, Germany, Luck, H., Editor(s), 419-428
Fire Safety Journal, Vol. 29, 129-139, 1997.
fire detection; experiments; data analysis; ceilings;
beams; computer programs; joists
The National Institute of Standards and Technology
(NIST) is conducting a four-year research project where
in a computational fluid dynamics (CFD) computer code is
utilized to map temperature, flow velocities, and
particle densities in spaces with complex ceiling
geometries. Through parametric variation of independent
variables for the fire and the space, the number and
location of smoke or thermal sensors required to assure
response prior to a critical fire size is determined.
The first year addressed horizontal ceilings with open
beams or joists, and the second year adds sloped
ceilings. In addition to the geometric studies, several
special studies have been conducted. These include
detection of low energy fires (as low as 100 Watts),
stratification of fire gases in spaces with a vertical
thermocline which exceeds the plume temperature, and
obstructions which do not come completely to the
ceiling. A unique method of relating the response of
detectors to the predicted conditions has been developed
which can be utilized with any CFD model or with
experimental data. The data analysis is being used to
produce siting rules for inclusion directly into
existing codes. The paper will review the results of
the first two years of the project and present some
thoughts on the potential for these techniques to
greatly improve the technical basis for the utilization
of fire sensors in complex installations.