Accession Number : ADP009017

Title :   Tunable Diode Laser Absorption Technique for Multi-Parameter Measurements of Combustion Flows,

Corporate Author : STANFORD UNIV CA DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Arroyo, M. P. ; Hanson, R. K.

Report Date : 23 JUL 1992

Pagination or Media Count : 6

Abstract : A tunable diode laser diagnostic based spectrally resolved laser absorption has been developed to detect water vapor. The system uses a distributed feedback InGaAsP diode laser, emitting around 1.385 micrometer. The diode laser is tuned in wavelength by modulating its driving current at frequencies up to 5 KHz Temperatures, concentrations and pressures are inferred from the directly measured absorption spectra. Velocity is derived from the Doppler shift of these absorption spectra. The technique has been demonstrated for multiple-parameter measurements of the water vapor present in laboratory room air, in the postflame gases above a methane-air flat fame burner and in the high speed unidimensional transient flows generated in a shock tube. The results agree well with the calculated valves and independent measurements. (Author)

Descriptors :   *WATER VAPOR, *GAS DYNAMIC LASERS, *ABSORPTION SPECTRA, COMBUSTION, METHANE, AIR WATER INTERACTIONS, CONCENTRATION(COMPOSITION), PRESSURE DISTRIBUTION, TEMPERATURE GRADIENTS, SHOCK TUBES, GAS FLOW, FIBER OPTICS, RESOLUTION, OPTICAL IMAGES, EXPERIMENTAL DATA, COMPARISON.

Subject Categories : Fluid Mechanics
      Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE