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Flame spread across liquid poolsFor flame spread over liquid fuel pools, the existing literature suggests three gravitational influences: (1) liquid phase buoyant convection, delaying ignition and assisting flame spread; (2) hydrostatic pressure variation, due to variation in the liquid pool height caused by thermocapillary-induced convection; and (3) gas-phase buoyant convection in the opposite direction to the liquid phase motion. No current model accounts for all three influences. In fact, prior to this work, there was no ability to determine whether ignition delay times and flame spread rates would be greater or lesser in low gravity. Flame spread over liquid fuel pools is most commonly characterized by the relationship of the initial pool temperature to the fuel's idealized flash point temperature, with four or five separate characteristic regimes having been identified. In the uniform spread regime, control has been attributed to: (1) gas-phase conduction and radiation; (2) gas-phase conduction only; (3) gas-phase convection and liquid conduction, and most recently (4) liquid convection ahead of the flame. Suggestions were made that the liquid convection was owed to both vuoyancy and thermocapillarity. Of special interest to this work is the determination of whether, and under what conditions, pulsating spread can and will occur in microgravity in the absence of buoyant flows in both phases. The approach we have taken to resolving the importance of buoyancy for these flames is: (1) normal gravity experiments and advanced diagnostics; (2) microgravity experiments; and (3) numerical modelling at arbitrary gravitational level.
Document ID
19930011020
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Ross, Howard
(NASA Lewis Research Center Cleveland, OH, United States)
Miller, Fletcher
(Case Western Reserve Univ. Cleveland, OH., United States)
Schiller, David
(California Univ. Irvine., United States)
Sirignano, William A.
(California Univ. Irvine., United States)
Date Acquired
September 6, 2013
Publication Date
February 1, 1993
Publication Information
Publication: The Second International Microgravity Combustion Workshop
Subject Category
Inorganic And Physical Chemistry
Accession Number
93N20209
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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