- Author
-
Hamins, A.
|
Gmurczyk, G. W.
|
Grosshandler, W. L.
|
Rehwoldt, R. G.
|
Vazquez, I.
|
Cleary, T. G.
|
Presser, C.
|
Seshadri, K.
- Title
- Flame Suppression Effectiveness.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
University of California at San Diego, La Jolla
- Report
-
NIST SP 861,
April 1994,
- Distribution
- Available from Government Printing Office
- Book or Conf
- Evaluation of Alternative In-Flight Fire Suppressants for Full-Scale Testing in Simulated Aircraft Engine Nacelles and Dry Bays. Section 4,
Grosshandler, W. L.; Gann, R. G.; Pitts, W. M., Editors,
345-465 p.,
1994
- Keywords
-
halons
|
fire suppression
|
effectiveness
|
diffusion flames
|
turbulent flames
|
premixed flames
|
detonation
|
chain reactions
- Identifiers
- opposed flow diffusion flames; coflowing; nonpremixed flames; turbulent spray flames; high speed premixed flames and quasi-detonations
- Abstract
- A flame will be extinguished when the time required for the chain reaction which sustains combustion exceeds the time it takes to replenish the necessary heat and reactants. A characteristic time for reaction can be estimated from the inverse of a global kinetic rate coefficient expressed in Arrhenius form as [equation] where B is a molecular collision frequency factor, Eo is a global activation energy, R is the ideal gas constant, and T is the gas temperature. Assuming reactant species and heat are transported at about the same rate (i.e., unity Lewis number), a characteristic time for replenishing both can be estimated from a convective flow velocity and a length scale by [equation].