- 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].