New Nonintrusive Laser Diagnostic Tools for Design and Optimization of Technically Applied Combustion Systems

Luczak, Andreas; Beushausen, Volker; Eisenberg, Sebastian; Knapp, Michael; Schlüter, Harald; Andresen, Peter L.; Malobabic, M.; Schmidt, A. A.

doi:10.1080/00102209608935562

Cited by 10 publications

(2 citation statements)

References 8 publications

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“…Laser interferometric techniques have already been extensively used in such environments for the characterization of the dispersed phase, as is also the case for the present study. On the other hand, laser spectroscopic techniques, that are virtually irreplaceable for temperature and species measurements in a turbulent environment, have been adapted only very recently to combusting sprays (Takahashi et al 1996;Luczak et al 1996), in some case through developments in our own laboratory (Karpetis & Gomez 1996). Consequently, this is the first study in which both types of diagnostic techniques, specifically Phase Doppler interferometry and spontaneous Raman scattering thermometry, are applied quantitatively in the same spray combustion system.…”

Section: Introductionmentioning

confidence: 99%

Self-similarity, momentum scaling and Reynolds stress in non-premixed turbulent spray flames

Karpetis

Gomez

1999

J. Fluid Mech.

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An experimental study was conducted in a turbulent spray flame in which droplets were produced ultrasonically at low velocity relative to the host gas. In this fashion, injector-specific effects on the two-phase flow were minimized and a scenario generally characteristic of the far field of practical spray systems could be simulated. Close to the burner exit, the spray flame appeared as a dense column of drops burning with an envelope flame. Further downstream, it opened up slowly in the radial direction and developed a turbulent ‘brush’ appearance. Measurements of the size, velocity and concentration of the droplets, and of gas-phase velocity and temperature were made by combining a Phase-Doppler interferometric technique with Stokes/anti-Stokes Raman thermometry. The experimental data were used to derive scaling and self-similarity for the Reynolds-averaged continuity and momentum equations using suitable transformations.Results showed three distinct regions, on the basis of the behaviour of the gas axial velocity in the spray flame. In the lower part of the flame, the gas momentum increased because of vaporization. In the intermediate region of the spray flame, the axial velocity decayed along the centreline as an inverse power of the distance from the virtual origin, with exponents smaller than unity. In the upper part of the spray flame, the flow field recovered the axial velocity decay that is typical of incompressible jets, namely as an inverse of the axial distance. Self-similar behaviour held for the axial velocity throughout the intermediate region. The vapour source term in the gas continuity equation scaled approximately as an inverse power of axial distance, and exhibited self-similarity throughout the spray flame. As a result, a simple model of the Reynolds stress term could be formulated, in which two competing contributions appear: one, that is due to turbulent transport, tends to increase the value of the velocity correlation; another, that is due to the vaporization term, tends to reduce the value of the velocity correlation and can be construed as a vaporization-induced tendency towards relaminarization. The first term is modelled by a classic gradient-transport approach yielding an empirical mixing length relating the velocity correlation to the average velocity gradient. Model and experiments are found to be in good agreement, especially sufficiently far from the injector, where one-way coupling between the two phases holds.

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Section: Introductionmentioning

confidence: 99%

Self-similarity, momentum scaling and Reynolds stress in non-premixed turbulent spray flames

Karpetis

Gomez

1999

J. Fluid Mech.

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“…Because of its strong signal intensity, LIF has been applied to 2D detection of temperature and species concentration [7,8]. These applications include basic research burners [9][10][11][12][13][14][15][16][17][18][19][20][21], industrial burners [4,22,23], gas turbines [4,24], and diesel engines [4,5,[25][26][27][28][29][30]. Recently, 3D detection [31,32] has also been shown to be capable of detecting several 2D sections simultaneously [33].…”

Section: Introductionmentioning

confidence: 99%

Industrial applications of temperature and species concentration monitoring using laser diagnostics

Deguchi¹,

Noda²,

Fukuda³

et al. 2002

Meas. Sci. Technol.

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Industrial applications of laser diagnostics have been demonstrated for the purpose of clarifying combustor chemical reaction mechanisms, as well as temperature and harmful substance monitoring in large-scale burners and commercial plant exhaust ducts, and the combustion control of commercial plants. Laser induced fluorescence (LIF), laser induced breakdown spectroscopy (LIBS), and tunable diode laser absorption spectroscopy (TDLAS) have accordingly been applied in various industrial fields. In this study, temperature and species concentration were measured inside gas turbine combustors, a diesel engine, and a large-scale industrial burner using LIF. This technique introduces a new tool with respect to practical combustors for the analysis of NO formation characteristics, turbulent flame front structure, and differences between standard and improved combustors. On-line monitoring of trace elements to the ppb level was also successfully demonstrated using LIBS. The automated LIBS unit was found to be capable of monitoring trace element concentration fluctuations at ppb levels with a 1 min detection time under actual plant conditions. In addition, real-time measurement of O2 and CO concentrations in a commercial incinerator furnace was performed using TDLAS to improve the combustion control. By using the multiple-point laser measurement results to control secondary air allocation, higher secondary combustion efficiency was achieved, and CO concentration (considered to be a substitute indicator for dioxins) was reduced from 11.9 to 8.0 ppm.

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Time-resolved polarization lock-in filtering for background suppression in Raman spectroscopy of biomass pyrolysis

Kim

Gong

Kristensson

et al. 2021

Combustion and Flame

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New Nonintrusive Laser Diagnostic Tools for Design and Optimization of Technically Applied Combustion Systems

Cited by 10 publications

References 8 publications

Self-similarity, momentum scaling and Reynolds stress in non-premixed turbulent spray flames

Self-similarity, momentum scaling and Reynolds stress in non-premixed turbulent spray flames

Industrial applications of temperature and species concentration monitoring using laser diagnostics

Time-resolved polarization lock-in filtering for background suppression in Raman spectroscopy of biomass pyrolysis

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