The Infrared Signature of Pyrophorics

Abstract

The infrared emission characteristics of six pyrophoric mixtures have been investigated at simulated altitudes up to 60,000 feet and the data compared to kerosene burned under the same conditions. The experiments were performed in large vacuum chambers with the mass flow rate being varied from 1 to 5 grams per second. Pyrophoric mixtures were atomized in a mixing nozzle by nitrogen and released as unchoked exhaust plumes. One series of tests demonstrated that the mixtures: (1) spontaneously ignited at all simulated altitudes, (2) emitted solely in the CO2 (4.2 to 4.4 microns) and the H2O (2.5 to 3.3 microns) bands, (3) resulted in radiation figures of merit above 200 watts/steradian/gram/second and (4) had an ignition time between 5 and 20 milliseconds. A second series of tests were performed with a co-flowing airstream created by releasing air into the vacuum chamber through a choke. These tests demonstrated the significant effect of airflow on the radiant intensity of unchoked exhaust plumes. A chemical equilibrium computer program was used to gain insight into other parameters affecting infrared radiation. Plume temperatures and the distribution of significant exhaust species were computed as a function of mixture ratio.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
May 01, 1974
Accession Number
AD0921319

Entities

People

  • C. W. Martin
  • Davut B. Ebeoglu

Tags

Communities of Interest

  • Weapons Technologies

DTIC Thesaurus Topics

  • Aerial Targets
  • Air Force Facilities
  • Combustion
  • Computer Programs
  • Exhaust Gases
  • Exhaust Plumes
  • Figure Of Merit
  • Flow Rate
  • Ignition
  • Infrared Radiation
  • Mass Flow
  • Materials
  • Measurement
  • Pyrophoric Materials
  • Radiant Intensity
  • Test And Evaluation
  • Vacuum Chambers

Fields of Study

  • Physics

Readers

  • Combustion and Flow Dynamics.
  • Combustion science or combustion engineering.
  • Spectroscopy.