- Author
-
Berlad, A. L.
|
Joshi, N. D.
- Title
- Gravitational Effects on the Extinction Conditions for Premixed Flames.
- Coporate
- California Univ., San Diego Univ., La Jolla
New York State Univ., Stony Brook
- Sponsor
- National Aeronautics and Space Admin., Washington, DC
- Report
-
A85-13089,
- Book or Conf
- International Astronautical Federation. International Astronautical Congress, 35th. IAF-84-151. October 7-13, 1984.,
Lausanne, Switzerland,
9 p.,
1984
- Keywords
-
extinction
|
flame propagation
|
flame stability
|
gravitational effects
|
premixed flames
|
flammability
|
weightlessness
- Identifiers
- spacecraft
- Abstract
- Theory and experiment for premixed gaseous and premixed particle-cloud flames are discussed. The roles of low temperature endothermicities in both kinds of premixed flames are found to be important determinants of flame properties, including extinction limits. Such findings are not found where truncated, overall reaction rate laws are used. Premixed stabilized lycopodium-air flames have been studied for upward (g = +1) and downward (g = -1) propagation under normal gravitational conditions, as well as under microgravity (g = 0) conditions. A single, self-contained apparatus was used in all studies. The roles of cold boundary heat losses, flame structure, competing energy transport processes, and gravitational conditions are identified and discussed. In general, gravitationally-induced processes and omni-directional radiative loss rates are found to be more significant flame structure determinants than molecular conductive losses to cold boundaries.