Suppression of Bluff-Body Stabilized Pool Flames

Abstract

The suppression mechanisms of a nonpremixed flame stabilized behind a backward-facing step in a wind tunnel have been studied using a gaseous fire-extinguishing agent (Halon 1301, bromotrifluoromethane) into the airflow. Methane or JP-8 jet fuel was used to simulate a pool fire behind a clutter in the aircraft engine nacelle. The characteristic mixing time in the recirculation zone in the wake was measured by impulsively injecting salt water mist into the airflow and by determining a time constant for the exponential decay of the sodium D-line emission at high temperatures. For both methane and JP-8 fuels under relatively high air velocities, the dependence of the critical agent mole fraction at extinction on the injection period is predictable using the characteristic mixing time and the minimum agent mole fraction, which is a fuel property measurable by a steady-state cup-burner method.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1999
Accession Number
ADA379646

Entities

People

  • F. Takahashi
  • V. M. Belovich
  • W. J. Schmoll

Organizations

  • Air Force Research Laboratory

Tags

Communities of Interest

  • Air Platforms
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Air Force
  • Air Force Facilities
  • Air Force Research Laboratories
  • Aircraft Engines
  • Computational Fluid Dynamics
  • Emission
  • Engine Nacelles
  • Engines
  • Extinction
  • Flow Rate
  • Fluid Dynamics
  • Fuels
  • High Temperature
  • Jet Engine Fuels
  • Liquids
  • Turbulent Mixing
  • Water

Fields of Study

  • Physics

Readers

  • Combustion science or combustion engineering.
  • Fire Suppression Systems Design.
  • Fluid Mechanics and Fluid Dynamics.