- Author
-
Ohlemiller, T. J.
- Title
- Modeling of Smoldering Combustion Propagation.
- Coporate
- National Bureau of Standards, Gaithersburg, MD
- Journal
-
Progress in Energy and Combustion Science,
Vol. 11,
277-310,
1985
- Report
-
NBSIR 84-2895; NBS SP 639
June 1984
111 p.
- Distribution
- Available from National Technical Information Service
- Book or Conf
- U.S./Japan Cooperative Program in Natural Resources. Fire Research and Safety. 5th Joint Panel Meeting. October 15-24, 1980,
Gaithersburg, MD,
Chidester, J. E., Editors,
266-307 p.,
['1980', '1984']
- Keywords
-
cellulosic materials
|
combustion
|
plastics
|
polyurethane foams
|
smoldering combustion
- Abstract
- Smoldering combustion, which can pose a serious life safety hazard, is encountered most frequently in various cellulosic materials and in open-cell polyurethane foams. It is probable that the principal heat source driving this process is heterogeneous oxidation but gas phase reactions may also contribute at higher temperatures. The chemistry involved is best-defined for the case of pure cellulose but even here the details are limited and actual mechanisms poorly understood; simplified kinetic descriptions, typically derived from isothermal or thermoanalytical experiments, currently provide the only tractable inputs for smoldering combustion models. The general problem of smolder wave propagation through a permeable bed of fuel particles is posed; coupled to the chemistry, one must also consider the physical processes of heat and mass transfer on both the particle scale and on the smolder wave scale. The general equations can be somewhat simplified, after non-dimensionalization, for cases where certain dimensionless parameters are very large or very small compared to unity. Existing smolder propagation models are all greatly simplified compared to this general model, neglecting gradients on the particle scale and considering only one-dimensional gradients on the wave scale. These models are reviewed; their contributions and deficiencies are noted.