Heat transfer in compartment fires near regions of ceiling-jet impingement on a wall

Journal Article · Mon May 01 00:00:00 EDT 1989 · Journal of Heat Transfer (Transactions of the ASME (American Society of Mechanical Engineers), Series C); (United States)

DOI:https://doi.org/10.1115/1.3250698· OSTI ID:6063105

Cooper, L Y ^[1]

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1. National Bureau of Standards, Gaithersburg, MD (United States)

The problem of heat transfer to walls from fire-plume-driven ceiling jets during compartment fires is introduced. Estimates are obtained for the mass, momentum, and enthalpy flux of the ceiling jet immediately upstream of the ceiling-wall junction. An analogy is drawn between the flow dynamics and heat transfer at ceiling-jet/wall impingement and at the line impingement of a wall and a two-dimensional, plane, free jet. Using the analogy, results from the literature on plane, free-jet flows and corresponding wall-stagnation heat transfer rates are recast into a ceiling-jet/wall-impingement-problem formulation. This leads to a readily usable estimate for the heat transfer from the ceiling jet as it turns downward and begins its initial descent as a negatively buoyant flow along the compartment walls. Available data from a reduced-scale experiment provide some limited verification of the heat transfer estimate. Depending on the proximity of a wall to the point of plume-ceiling impingement, the result indicates that for typical full-scale compartment fires with energy release rates in the range 200-2,000 kW and fire-to-ceiling distances of 2-3 m, the rate of heat transfer to walls can be enhanced by a factor of 1.1-2.3 over the heat transfer to ceilings immediately upstream of ceiling-jet impingement.

• OSTI ID: 6063105
• Journal Information: Journal of Heat Transfer (Transactions of the ASME (American Society of Mechanical Engineers), Series C); (United States), Journal Name: Journal of Heat Transfer (Transactions of the ASME (American Society of Mechanical Engineers), Series C); (United States) Vol. 111:2; ISSN 0022-1481; ISSN JHTRA
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
570000 -- Health & Safety
99 GENERAL AND MISCELLANEOUS
BUILDINGS
CALCULATION METHODS
CONVECTION
DATA
ENERGY TRANSFER
FIRES
HEAT TRANSFER
IMPINGEMENT
INFORMATION
JETS
MASS TRANSFER
NATURAL CONVECTION
NUMERICAL SOLUTION
SCALE MODELS
STRUCTURAL MODELS
WALLS