Gas Turbine Exhaust Emissions Monitoring Using Nonintrusive Infrared Spectroscopy

1998 ◽  
Vol 120 (3) ◽  
pp. 514-518 ◽  
Author(s):  
M. Hilton ◽  
A. H. Lettington ◽  
C. W. Wilson
Keyword(s):  
Gas Turbine ◽  
Molecular Species ◽  
Tomographic Reconstruction ◽  
Emission Spectra ◽  
Exhaust Emissions ◽  
Infrared Emission ◽  
High Spectral Resolution ◽  
Rotational Line ◽  
Spectroscopic Techniques ◽  
Reconstruction Procedure

Infrared (IR) spectra of the exhaust emissions from a static gas turbine engine have been studied using Fourier Transform (FT) spectroscopic techniques. Passive detection of the infrared emission from remote (range ∼ 3 m) hot exhaust gases was obtained nonintrusively using a high spectral resolution (0.25 cm−1) FTIR spectrometer. Remote gas temperatures were determined from their emission spectra using the total radiant flux method or by analysis of rotational line structure. The HITRAN database of atmospheric species was used to model the emission from gas mixtures at the relevant temperatures. The spatial distribution of molecular species across a section transverse to the exhaust plume ∼10 cm downstream of the jet pipe nozzle was studied using a tomographic reconstruction procedure. Spectra of the infrared emission from the plume were taken along a number of transverse lines of sight from the centerline of the engine outwards. A mathematical matrix inversion technique was applied to reconstruct the molecular concentrations of CO and CO2 in concentric regions about the centerline. Quantitative measurement of the molecular species concentrations determined nonintrusively were compared with results from conventional extractive sampling techniques.

scholarly journals Gas Turbine Exhaust Emissions Monitoring Using Non-Intrusive Infrared Spectroscopy

1997 ◽  
Author(s):  
Moira Hilton ◽  
Alan H. Lettington ◽  
Chris W. Wilson
Keyword(s):  
Gas Turbine ◽  
Molecular Species ◽  
Tomographic Reconstruction ◽  
Emission Spectra ◽  
Exhaust Emissions ◽  
Infrared Emission ◽  
High Spectral Resolution ◽  
Rotational Line ◽  
Spectroscopic Techniques ◽  
Reconstruction Procedure

Infrared (IR) spectra of the exhaust emissions from a static gas turbine engine have been studied using Fourier Transform (FT) spectroscopic techniques. Passive detection of the infrared emission from remote (range ∼ 3 m) hot exhaust gases was obtained non-intrusively using a high spectral resolution (0.25 cm−1) FTIR spectrometer. Remote gas temperatures were determined from their emission spectra using the total radiant flux method or by analysis of rotational line structure. The HITRAN database of atmospheric species was used to model the emission from gas mixtures at the relevant temperatures. The spatial distribution of molecular species across a section transverse to the exhaust plume −10 cm downstream of the jet pipe nozzle was studied using a tomographic reconstruction procedure. Spectra of the infrared emission from the plume were taken along a number of transverse lines of sight from the centreline of the engine outwards. A mathematical matrix inversion technique was applied to reconstruct the molecular concentrations of CO and CO2 in concentric regions about the centreline. Quantitative measurements of the molecular species concentrations determined non-intrusively were compared with results from conventional extractive sampling techniques.

The Use of Ratio-Recording Interferometry for the Measurement of Infrared Emission Spectra: Applications to Oxide Films on Copper Surfaces

1975 ◽  
Vol 29 (6) ◽  
pp. 496-500 ◽  
Author(s):  
D. Kember ◽  
N. Sheppard
Keyword(s):  
Emission Spectra ◽  
Black Body ◽  
Infrared Emission ◽  
Thin Layers ◽  
Oxide Surface ◽  
Surface Layers ◽  
Selective Reflection ◽  
Copper Surfaces ◽  
Emission And Absorption Spectra ◽  
Direct Correspondence

Infrared emission spectra from metal samples with oxide surface layers are shown to be very advantageously studied using the spectrum-ratioing facility of a recording infrared interferometer. The emission from a given sample is ratioed against that from a black-body emitter at the same temperature so as to give emittance as a function of wavenumber directly. This method has very useful application to irregularly shaped metal emitters. In the absence of selective reflection there is a direct correspondence between emission and absorption spectra for thin layers of an emitting substance. However, the presence of selective reflection leads to reduced emission and to considerable differences in the appearance of “absorption” and emission spectra in regions of strong absorption. Emission spectra obtained from copper plates heated, above 150°C, for different periods in air are shown clearly to indicate the presence of cuprous, Cu(I), and cupric, Cu(II), oxides in the surface layer.

Infrared emission spectra of BeH2 and BeD2

2003 ◽  
Vol 118 (8) ◽  
pp. 3622-3627 ◽  
Author(s):  
A. Shayesteh ◽  
K. Tereszchuk ◽  
P. F. Bernath ◽  
R. Colin
Keyword(s):  
Emission Spectra ◽  
Infrared Emission

Temperature Gradients Through EHD Films and Molecular Alignment Evidenced By Infrared Spectroscopy

1981 ◽  
Vol 103 (1) ◽  
pp. 65-73 ◽  
Author(s):  
V. W. King ◽  
J. L. Lauer
Keyword(s):  
Absorption Spectrum ◽  
Emission Spectra ◽  
Infrared Emission ◽  
Molecular Alignment ◽  
Temperature Gradients ◽  
Spectral Change ◽  
Continuum Source ◽  
Polyphenyl Ether ◽  
Elementary Analysis ◽  
Gap Width

Partial and complete emission band reversals have been observed in the infrared emission spectra from portions of operating sliding contacts. An elementary analysis has been carried out to show that partial reversals are due to temperature gradients in the fluid film—the film acts both as a radiation-emitter and absorber, and that total reversals—an emission spectrum appears as an absorption spectrum—are likely to be due to a continuum source, such as hot solid asperities. The total energy radiated under the latter conditions exceeds that under the others. A decrease in gap width with increased load was accompanied by a dramatic spectral change in the case of 5P4E polyphenyl ether, which is indicative of molecular alignment.

Searching for 3D effects in the optical, high spectral resolution emission spectrum of KELT-9b

2021 ◽  
Author(s):  
Lorenzo Pino ◽  
Matteo Brogi ◽  
Jean-Michel Désert ◽  
Emily Rauscher
Keyword(s):  
Emission Spectrum ◽  
Spectral Resolution ◽  
Planet Formation ◽  
Emission Spectra ◽  
Optical Emission ◽  
High Spectral Resolution ◽  
Optical Emission Spectrum ◽  
Hot Jupiters ◽  
Atmospheric Structure ◽  
3D Effects

<p>Ultra-hot Jupiters (UHJs; T<sub>eq</sub> ≥ 2500 K) are the hottest gaseous giants known. They emerged as ideal laboratories to test theories of atmospheric structure and its link to planet formation. Indeed, because of their high temperatures, (1) they likely host atmospheres in chemical equilibrium and (2) clouds do not form in their day-side. Their continuum, which can be measured with space-facilities, can be mostly attributed to H- opacity, an indicator of metallicity. From the ground, the high spectral resolution emission spectra of UHJs contains thousands of lines of refractory (Fe, Ti, TiO, …) and volatile species (OH, CO, …), whose combined atmospheric abundances could track planet formation history in a unique way. In this talk, we take a deeper look to the optical emission spectrum of KELT-9b covering planetary phases 0.25 - 0.75 (i.e. between secondary eclipse and quadrature), and search for the effect of atmospheric dynamics and three-dimensionality of the planet atmosphere on the resolved line profiles, in the context of a consolidated statistical framework. We discuss the suitability of the traditionally adopted 1D models to interprete phase-resolved observations of ultra-hot Jupiters, and the potential of this kind of observations to probe their 3D atmospheric structure and dynamics. Ultimately, understanding which factors affect the line-shape in UHJs will also lead to more accurate and more precise abundance measurements, opening a new window on exoplanet formation and evolution.</p>

scholarly journals Modeling the Anharmonic Infrared Emission Spectra of PAHs: Application to the Pyrene Cation

2020 ◽  
pp. 95-102
Author(s):  
M. Basire ◽  
P. Parneix ◽  
T. Pino ◽  
Ph. Bréchignac ◽  
F. Calvo
Keyword(s):  
Emission Spectra ◽  
Infrared Emission

scholarly journals Laser-Plasma and Self-Absorption Measurements with Applications to Analysis of Atomic and Molecular Stellar Astrophysics Spectra

Atoms ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 63 ◽  
Author(s):  
Christian G. Parigger ◽  
Christopher M. Helstern ◽  
Ghaneshwar Gautam
Keyword(s):  
Molecular Species ◽  
Laser Plasma ◽  
Emission Spectra ◽  
Hydrogen Gas ◽  
Spectral Radiance ◽  
Pure Hydrogen ◽  
Line Profiles ◽  
Emission Data ◽  
Balmer Series ◽  
Gaseous Mixtures

This work discusses laboratory measurements of atomic and diatomic molecular species in laser-plasma generated in gases. Noticeable self-absorption of the Balmer series hydrogen alpha line occurs for electron densities of the order of one tenth of standard ambient temperature and pressure density. Emission spectra of selected diatomic molecules in air or specific gaseous mixtures at or near atmospheric pressure reveal minimal plasma re-absorption. Abel inversion of the plasma in selected gases and gas mixtures confirm expansion dynamics that unravel regions of atomic and molecular species of different electron temperature and density. Time resolved spectroscopy diagnoses self-absorption of hydrogen alpha and hydrogen beta lines in ultra-high pure hydrogen gas. Radiation from a Nd:YAG laser device induces micro-plasma for pulse widths in the range of 6–14 ns, energies in the range of 100–800 mJ, and peak irradiances of the order 1–10 TW/cm 2 . Atomic line profiles yield electron density and temperature from fitting of line profiles to wavelength and sensitivity corrected spectral radiance data. Analysis of measured diatomic emission data yields excitation temperature of primarily molecular recombination spectra. Applications of the laboratory experiments extend to investigations of stellar astrophysics white dwarf spectra.

scholarly journals Infrared Emission Spectra of CaF2-CaO-SiO2 Melt.

2000 ◽  
Vol 40 (8) ◽  
pp. 739-743 ◽  
Author(s):  
Shigeru Ueda ◽  
Hirotaka Koyo ◽  
Takashi Ikeda ◽  
Yoshiharu Kariya ◽  
Masafumi Maeda
Keyword(s):  
Emission Spectra ◽  
Infrared Emission
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