Sage Journals: Discover world-class research

Abstract

Experimental improvements have been made in the UV-visible absorption spectroscopy technique applied to propellant flame diagnostics. The two-dimensional feature of an intensified charge-coupled device (CCD) 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 pathlength through the combustion region. Due to broadband UV-visible absorption observed in propellant flame spectra, typically only 20% of the incident light is transmitted. However, inclusion of a neutral-density filter during the measurement of the incident intensity I₀ 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 with two different propellant flames.

Keywords

Absorption spectroscopy Propellants Diagnostics

Get full access to this article

View all access options for this article.

References

Ulas

Y. C.

and Kuo

K. K

, “Determination of Temperature and OH Concentration Profiles of RDX/CAB Pseudo Propellant Using UV/Visible Absorption Spectroscopy”, in Challenges in Propellant and Combustion, 100 Years After Nobel, Kuo

K. K.

, Ed. (Begell House, New York, 1997), p. 885.

Vanderhoff

J. A.

and Kotlar

A. J

, “Simultaneous Determination of Temperature and OH Concentrations in a Solid Propellant Flame”, 23rd Symp. on Combustion (The Combustion Institute, Pittsburgh, Pennsylvania, 1990), p. 1339.

Teague

M. W.

Singh

and Vanderhoff

J. A

, “Spectral Studies of Solid Propellant Combustion IV: Absorption and Burn Rate Results for M9, XM39, and M10 propellants”, ARL Technical Report, ARL-TR-180 (1993), p. 1.

Vanderhoff

J. A.

Teague

M. W.

and Kotlar

A. J

, “Determination of Temperature and NO Concentrations Through the Dark Zone of Solid-Propellant Flames”, 24th Symposium on Combustion (The Combustion Institute, Pittsburgh, Pennsylvania, 1992), p. 1915.

Y. C.

Freyman

and Kuo

K. K

, “Measurement of Temperatures and OH Concentrations of Solid Propellant Flames using Absorption Spectroscopy”, Proceedings of the 31st JANNAF Subcommittee Meeting, CPIA Publ. 620 (1994), p. 277.

Parr

and Hanson-Par

, “Solid Propellant Flame Structure”, in Decompositon, Combustion, and Detonation Chemistry of Energetic Materials, Brill

T. B.

Russel

T. P.

Tao

W. C.

and Wardle

R. B

, Eds. (Material Research Society, Pittsburgh, Pennsylvania, 1995), vol. 418, p. 207.

Mallery

C. F.

and Thynell

S. T

, “Species and Temperature Profiles of Propellant Flames Obtained from FTIR Absorption Spectroscopy”, Proceedings of the 31st JANNAF Subcommittee Meeting, CPIA Publ. 620 (1994), p. 219.

Homan

B. E.

Miller

M. A.

and Vanderhoff

J. A

, “Absorption Diagnostics and Modeling Investigations of RDX Flames”, accepted by Combustion and Flame (1999).

Beck

, Rev. Sci. Instrum. 45, 318 (1974).

10.

Smit

K. J.

, J. Energetic Mat. 9, 81 (1991).

11.

Vanderhoff

J. A.

and Kotlar

A. J

, “Improving Spectral Fits of Absorption Data taken with an Array Detector: Wavelength Linearization”, BRL Technical Report, BRL-MR-3866 (1990), p. 1.

12.

Beckstead

M. W.

and Erikson

W. W

, “Combustion Instability of Solid Monopropellant”, Proceedings of the 33rd JANNAF Subcommittee Meeting, CPIA Publ. 653 (1996), p. 145.

Snapshot Absorption Spectroscopy

Abstract

Keywords

Get full access to this article

References