Accession Number:

ADA625169

Title:

X-ray Fluorescence Measurements of Turbulent Methane-Oxygen Shear Coaxial Flames

Descriptive Note:

Technical paper Jan-May 2015

Corporate Author:

AIR FORCE RESEARCH LAB EDWARDS AFB CA AEROSPACE SYSTEMS DIRECTORATE

Report Date:

2015-05-01

Pagination or Media Count:

12.0

Abstract:

The use of x-ray fluorescence to make quantitative mixing field measurements in high temperature flames is attractive due to a number of positive attributes of x-ray fluorescence physics, particularly insensitivity to chemical bonding which results in tracers being conserved in the flame and negligible beam steering effects. To demonstrate the use of x-ray fluorescence in high temperature flames, the technique was applied to turbulent methane-oxygen shear coaxial flames. These flames are directly applicable to the oxygen-enriched combustion that occurs in liquid rocket engines where, due to the high temperature, it is difficult to obtain quantitative mixing field measurements using conventional optical diagnostics. The use of argon and krypton as x-ray fluorescence flow tracers was explored. Krypton was shown to require fewer corrections than the argon background argon signal subtraction and signal trapping corrections were required. To allow tracking of both the fuel and oxidizer stream, cases were run where the tracer element was moved from the oxygen stream to the fuel stream. Comparison of the fuel traced and oxygen traced cases are compared to build a more complete picture of the reacting flow field. Results clearly demonstrate the ability of x-ray fluorescence to obtain quantitative measurements of projected density in high temperature flames. This work represents the first use of x-ray fluorescence to make quantitative tracer projected density measurements in turbulent flames.

Subject Categories:

  • Inorganic Chemistry
  • Nuclear Physics and Elementary Particle Physics
  • Combustion and Ignition

Distribution Statement:

APPROVED FOR PUBLIC RELEASE