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Analysis of FDS Thermal Detector Response Prediction Capability.


pdf icon Analysis of FDS Thermal Detector Response Prediction Capability. (3775 K)
Hurley, M. J.; Munguia, A.

NIST GCR 09-921; 105 p. January 2009.

Sponsor:

National Institute of Standards and Technology, Gaithersburg, MD

Keywords:

experiments; fire plumes; ceiling jets; temperature; thermal detectors; detector response; large scale fire tests; compartments; ceiling height; heat release rate; thermocouples; simulation; spacing; test data; computer models; thermal properties; uncertainity

Abstract:

Predictions of fire plume and ceiling jet temperature and the response of thermal detectors from NIST's Fire Dynamics Simulator (FDS) were compared to data from a series of full-scale tests conducted by Underwriters Laboratory. The tests were conducted in a 36.6 m x 36.6 m compartment with ceiling heights ranging from 3.0 meters to 12.2 meters. Heat release rates followed a modified t2 growth profile. Thermocouples attached to brass disks were used to simulate thermal detectors. FDS simulations were conducted with a grid spacing of 100 mm. A convergence study found that grid-size convergence was achieved outside of the plume region. However, grid convergence was not achieved in the plume region at this grid spacing. Outside of the plume region, FDS predictions were within a factor of 1.9 of test data.