Accession Number:

ADA370349

Title:

Spatially Resolved Combustion Species and Temperatures of Solid Propellant Flames Using Snapshot Spectroscopy

Descriptive Note:

Final rept. Aug 96-Aug 98

Corporate Author:

ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD

Report Date:

1999-10-01

Pagination or Media Count:

32.0

Abstract:

Experimental improvements have been made in the ultraviolet UV-visible absorption spectroscopy technique applied to propellant flame diagnostics. The two-dimensional 2-D feature of an intensified charge-coupled device ICCD detector was used to simultaneously record multiple, spatially distinct absorption spectra over a region of 0.35 cm. Temporal resolution has been increased to 1 ms by pulsing a simmering xenon arc lamp. The resulting increase in the light intensity by 30 to 70 times over the nonpulsed output provides the necessary light flux to achieve single-pulse, multiple absorption spectra. Species with low concentrations can be measured with the inclusion of multiple-pass optics to increase the effective path length through the combustion region. Due to broadband UV-visible absorption observed in propellant flame spectra, only 20 of the incident light is typically transmitted. However, inclusion of a calibrated neutral density filter during the measurement of the incident intensity I sub 0 allows the dynamic range of the detector to be effectively increased by a factor of 5. With these improvements, temperature and OH and NO concentration maps, with 1-ms temporal resolution, have been determined for two different propellant flames.

Subject Categories:

  • Combustion and Ignition

Distribution Statement:

APPROVED FOR PUBLIC RELEASE