Modeling of aspects of large-area fires. Technical report, 19 July 1984-29 April 1985

Technical Report · Tue Apr 30 04:00:00 EDT 1985

OSTI ID:5338820

Carrier, G F; Fendell, F E; Hsu, C T

The theoretical part of this study seeks to identify the simplest physically reasonable extension ( of integral-type theory for the buoyant plume over a finite-area quasisteady fire) that permits description of saturation and condensation of water vapor, if they occur. The plume is subdivided axially into three zones: (1) a low-level fire zone in which entrainment appreciably enhanced over Morton-Taylor-Turner levels occurs, but only that water vapor associated with combustion need be accounted for; (2) a higher zone (lying above the completion-of-burning altitude but below the saturation-of-water vapor altitude, under the assumption that such saturation occurs prior to updraft stagnation), in which entrainment of water vapor from the ambient occurs; and (3) a still higher zone bounded below by saturation and above by stagnation, in which further entrainment of ambient vapor may be negligible. Condensation of water vapor is of long-standing interest in terms of the possible additional lofting of smoke owing to release of condensational heat, and in terms of the possible self-extinction of fires in moist environments. The possible role of (condensed) water in enhancing the coagulation of submicron-sized soot is also of interest in terms of the nuclear-winter context. In the experimental part, was undertaken for flow preparation upwind of the test section in a fire tunnel designed for measuring wind-aided fire spread across a regularly arranged, two-dimensional array of discrete polymeric fuel elements. In particular, hot-wire measurements have quantified the deviations from uniform streaming (in a time-averaged sense) across the leading edge of the fuel matrix and have suggested design alternations.

• Research Organization: TRW Electronics and Defense Sector, Redondo Beach, CA (USA)
• OSTI ID: 5338820
• Report Number(s): AD-A-168809/2/XAB; TRW-42504-6002-UT-00
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400800 -- Combustion
Pyrolysis
& High-Temperature Chemistry
45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
450202* -- Explosions & Explosives-- Nuclear-- Weaponry-- (-1989)
CHEMICAL REACTIONS
COMBUSTION
ENTRAINMENT
EXPLOSIONS
FIRES
FLAME PROPAGATION
FLUIDS
FUELS
GASES
HYDROGEN COMPOUNDS
MOISTURE
NUCLEAR EXPLOSIONS
NUCLEAR WINTER
OXIDATION
OXYGEN COMPOUNDS
PLUMES
POLYMERS
SATURATION
SOOT
STREAMS
SURFACE WATERS
THERMOCHEMICAL PROCESSES
VAPORS
WATER
WATER VAPOR
WIND