Open AccessCombined use of TDLAS and LIBS for reconstruction of temperature and concentration fields
Author(s) -
Jungwun Lee,
Cheolwoo Bong,
Jihyung Yoo,
Moon Soo Bak
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.396909
Subject(s) - materials science , tunable diode laser absorption spectroscopy , water vapor , thermocouple , attenuation coefficient , combustion , temperature measurement , optics , analytical chemistry (journal) , absorption spectroscopy , absorption (acoustics) , absorbance , spectroscopy , laser , tunable laser , chemistry , thermodynamics , physics , organic chemistry , chromatography , quantum mechanics , composite material
A new technique is developed for reconstructing the temperature and species-concentration fields by employing tunable diode laser absorption spectroscopy (TDLAS) and laser-induced breakdown spectroscopy (LIBS) on axisymmetric combustion fields. For two-line thermometry, the uncertainties in linestrengths of the absorption lines may cause systematic errors in temperature and species concentration estimations. Thus, the radial profiles of water vapor concentration are obtained first using the LIBS, assuming that the combustion is complete; then, the radial temperature profiles are estimated from the radial profiles of absorption coefficient, as reconstructed from the absorbance profiles obtained using the TDLAS. The spectral lines of water vapor at 7185.6 and 7444.36 cm -1 are selected as the linestrengths show monotonic decreases with the increase in temperature within the measuring temperature range. The radial profiles of temperature and water mole fraction are well-reconstructed, and the measurement error is found to be as low as 3%. The technique yielded higher temperatures compared to the thermocouple, possibly owing to the significant radiative heat loss in the thermocouple data.