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Author
Prasad, K. R. | Patnaik, G. | Kailasanath, K.
Title
Advanced Simulation Tool for Improved Damage Assessment:1) A Multiblock Technique for Simulation Fire Smoke Spread in Large Complex Enclosures.
Coporate
Naval Research Laboratory, Washington, DC
Sponsor
Office of Naval Research, Arlington, VA
Report
NRL Memorandum Report, February 21, 2000, 28 p.
Distribution
AVAILABLE FROM National Technical Information Service (NTIS), Technology Administration, U.S. Department of Commerce, Springfield, VA 22161. Telephone: 1-800-553-6847 or 703-605-6000; Fax: 703-605-6900. Website: http://www.ntis.gov
Keywords
fire spread | flow fields | enclosures | air entrainment | smoke spread | detonation | combustion | fire simulation
Identifiers
multiblock technique
Abstract
Several recent developmenrs in computational techniques have been combined to develop a tool for simulating the reactive flow field inside large complex enclosures. The multiblock technique was adopted to solve the unsteady compressible Navier-Stokes equations inside a large fire compartment. Numerical simulations of a 330 kW and a 980 kW fire in a single uncluttered compartment have been performed. Peak ceiling jet temperature of 430 deg C and 910 deg C was computed, for the two fires, respectively. The multiblock approach efficiently grids regions of high heat release with a fine mesh embedded in a coarser mesh covering the larger compartment. It also allows flow field information to be exchanged with the surrounding air through the doorway. Temperature contours and instantaneous velocity vectors provide a detailed understanding of air entrainment into the fire and the flow of hot gases through the door. Numerical results have been found to compare favorably with experimental data. Computations are also reported for a 1310 kW fire in a multi-compartment geometry that replicates the ex-USS Shadwell. Peak temperatures of 320 deg C are obtained in this case. Our results predict a continuously evolving flow field as unsteady vortical structures are generated in the fire plume and convect through the various compartments via the doors and hatches.