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In order to provide insight into the fire growth and smoke movement in a tragic high rise office building fire that resulted in six fatalities and numerous injuries, NIST was asked to simulate the Cook County Administration Building fire using the Fire Dynamic Simulator (FDS) and Smokeview visualizations. The NIST team also documented the fire damage in order to compare fire model predictions with the observed physical damage. Undamaged interior finish materials and furnishings from the fire floor were obtained for use in laboratory scale heat release rate experiments. The heat release data was necessary
for the fire model input and allowed better evaluation with the results from the fire model.
The Governor of Illinois asked NIST to provide technical assistance to the Governor’s Review Team headed by James Lee Witt. The NIST team, headed by Daniel Madrzykowski, visited the fire scene to collect data for the model including building dimensions, floor plan, door and window locations, materials of construction and furnishings, and fuels. In addition, the Governor of Illinois’ team on fire service operations and building systems helped to develop the fire timeline.
The FDS simulation provided insight into the fire develop-ment. One simulation examined the impact of automatic fire suppression sprinklers. The results suggested that had automatic sprinklers been present in the storage room where the fire is believed to have originated, they would have controlled the fire and limited the fire spread to the room of fire origin. Other simulations examined the impact of the spread of smoke into the southeast stairway with and without a functioning smoke exhaust shaft.
To learn more about the experiments and the simulations, see NIST
Special Publication SP-1021, Cook County Administration Fire, 69 West Washington, Chicago, Illinois, October 17, 2003: Heat Release Rate Experiments and FDS Simulations, by Daniel Madrzykowski and William D. Walton. For more information, contact Dan Madrzykowski, daniel.madrzykowski@nist.gov.
Computer animation showing flame iso-surface in office suite at 7 min 30 s after flaming ignition.
Of the three types of forced ventilation (hydraulic, negative pressure, positive pressure), it is felt that positive pressure ventilation (PPV) is the most effective as it moves air from the outside of a structure to the inside. Firefighters may open or break windows and/or doors or create vent openings as needed to increase the effectiveness of PPV.
To better understand the gas velocities that occur during a fire, Stephen Kerber at NIST has run two full scale room fire experiments
to characterize the Positive Pressure Ventilation (PPV) fan in an open atmosphere and a simple room geometry. The data for the experiments are compared with simulations completed with a computational fluid dynamic model, the Fire Dynamic Simulator (FDS), and there was favorable agreement. With the correct geometry, vent placement and boundary location, FDS predicted velocities that were within 10 percent for the open atmosphere and 20 percent for the simple room geometry test. Future experiments are needed to
examine the flow in other structures such as multi-floor or those of more complex geometries.
A recent report, Characterizing Positive Pressure Ventilation Using Computational Fluid Dynamics by Stephen Kerber and William D. Walton, NISTIR 7065, describes the fire tests and comparison with FDS.
For additional information, you may contact Stephen at stephen.kerber@nist.gov.
Comparison between Experimental and FDS PPV flows.
