Rapid tuning cw laser technique for measurements of gas velocity, temperature, pressure, density, and mass flux using NO

Chang, Albert Y.; Dirosa, M. D.; Davidson, David F.; Hanson, Ronald K.

doi:10.1364/ao.30.003011

Cited by 45 publications

(14 citation statements)

References 20 publications

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“…6(b) is calculated as The values of integrated absorbance coefficient are substituted in Eq. (14), which is further solved by nonlinear programming to get the velocity distribution. The upper and lower bounds are given in the numerical case as constraints.…”

Section: Results and Analysismentioning

confidence: 99%

“…(14), the 2D velocity distribution can be reconstructed by solving an equivalent nonlinear programming problem as 21) is the least square approximation of the solution of Eq. (14). In this paper, Eq.…”

Section: La = a (19)mentioning

confidence: 99%

“…The distribution of velocities in the RoI is reconstructed by solving the nonlinear system described by Eq. (14).…”

Section: Reconstruction Of 2d Velocity Distributionmentioning

confidence: 99%

“…It has been more than two decades since laser absorption spectroscopy (LAS) was first used to measure gas flow velocity [14][15][16]. The flow velocity is calculated according to the Doppler shift of the absorption spectrum of a target molecule.…”

Section: Introductionmentioning

confidence: 99%

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Reconstruction of two-dimensional velocity distribution in scramjet by laser absorption spectroscopy tomography

Cao

et al. 2018

Appl. Opt.

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Received XX Month XXXX; revised XX Month, XXXX; accepted XX Month XXXX; posted XX Month XXXX (Doc. ID XXXXX); published XX Month XXXX We propose a method to reconstruct the two-dimensional (2D) velocity distribution of flow fields by laser absorption spectroscopy tomography. A mathematic model is established to reveal the dependence of spectral absorbance on line-of-sight velocity distribution. Then, with multiple laser beams from different angular views covering the region of interest, a nonlinear equation set of 2D velocity distribution is established according to the model. The integrated absorbance coefficient distribution is reconstructed using the Landweber iteration algorithm and substituted into the nonlinear equation set for further simplification. Finally, the velocity distribution is reconstructed by solving the simplified equation group via the interior-point algorithm. The proposed method is validated numerically by reconstructing the velocity distribution of water molecules, as calculated by Computational Fluid Dynamics, over a cross-section of a double-mode scramjet combustor. The method does not require adding extra tracer particles and avoids issues arising from the short lifetime of molecular tags. It is suitable for diagnosis of high-speed flow fields.

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Section: Results and Analysismentioning

confidence: 99%

Section: La = a (19)mentioning

confidence: 99%

“…The distribution of velocities in the RoI is reconstructed by solving the nonlinear system described by Eq. (14).…”

Section: Reconstruction Of 2d Velocity Distributionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Reconstruction of two-dimensional velocity distribution in scramjet by laser absorption spectroscopy tomography

Cao

et al. 2018

Appl. Opt.

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“…The first attempts were based on previous studies, such as (Philippe and Hanson, 1993) who fit the second harmonic profile with a fifth order polynomial. A second technique, inspired by a Voigt fit of absorption profiles in (Chang et al, 1991), attempted to fit the entire 2f feature with a polynomial derived from the theory presented in Section 2.1.1.2. While these methods proved successful in some cases, they required excessive user input to be properly applied to results with different sweep and modulation amplitudes.…”

Section: Velocity Measurementmentioning

confidence: 99%

Development of a Tunable Diode Laser Absorption Spectroscopy Mass-Flux Sensor for Quantifying Hydrocarbon Storage Tank Venting

Festa-Bianchet¹

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Fixed-roof liquid hydrocarbon storage tanks are a recognized source of volatile organic compounds and greenhouse gases. However, current emissions estimates suffer from a lack of reliable models due to poor in situ validation. This work presents the development and characterization of an intrinsically safe, low velocity mass-flux sensor for monitoring storage tank venting. The sensor is based on tunable diode laser absorption spectroscopy (TDLAS) with wavelength modulation. Similar sensors have been successfully used to measure high velocity flows, such as shock propagation and scramjet combustor exhaust. The oxygen within the vapour space of fixed-roof storage tanks is targeted in the near-IR as the absorption species. Sensor design, optimum operational parameters, and indoor characterization results are presented. An oxygen concentration precision of greater than 0.11% absolute was achieved over the tested range of 2.5 to 21% O2. For measurements at 21% O2, a velocity standard deviation of 0.24 m/s for 30-s average measurements was achieved, which could be improved to 0.

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Flow and Particle Diagnostics. Multi‐Parameter and Multi‐Point Measurements

Hanson

Baer

McMillin

et al. 1993

Ber Bunsenges Phys Chem

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Laser-based diagnostic techniques, developed primarily within the combustion community, offer considerable promise for nonintrusive measurements in gaseous flows relevant to industry. In this paper, we review two diagnostic methods under development in our laboratory. The first technique allows simultaneous measurement of multiple parameters through analysis of the shape and shift of fully resolved absorption lineshapes. The light source is a tunable, narrow-linewidth semiconductor diode laser, applied in the present case to either water vapor (1.39microns) at combustion gas temperatures (to 1700K) or to argon (800nm) in an atmospheric pressure plasma (at temperatures to 8000 K). Parameters inferred include, for water: temperature, pressure, velocity and species density; for argon, the parameters are electron density, kinetic temperature and the population temperature for the 4 s levels of argon. The second diagnostic technique is planar laser-induced fluorescence (PLIF), which allows instantaneous measurements of a single parameter at multiple points in the flowfield. The example application to be discussed is single-shot temperature imaging in a model scramjet flowfield using a two laser-two camera imaging scheme. Ber. Bunsenges. Phys. Chem. 97, 1548-1555 (1993) No. 12 0 VCH Verlagsgesellschqft mbH, 0-69451 Weinheim, 1993 0005-9021/93/A technique is presented for making instantaneous, two-dimensional measurements of the mixture fraction in turbulent nonpremixed flames. The technique uses acetaldehyde fluorescence imaging and Rayleigh imaging to determine the mixture fraction in an iterative manner. Preliminary experimental results for the mixture fraction and its gradient in a turbulent acetaldehyde flame are presented. To verify the degree to which the acetaldehyde fluorescence tracks the fuel concentration, simultaneous fluorescence and fuel Raman scattering measurements are performed. The strength of the signals from the Rayleigh scattering and the fuel fluorescence allows computations of the mixture fraction high in spatial resolution and low in noise, thus making determination of the scalar dissipation feasible. Ber. Bunsenges. Phys. Chem. 97, I555 -1559 11993) No. 12 %, VCH Verlagsgesellschaft mbH, 0-69451 Weinheim, 1993 W05-9021/93/

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Rapid tuning cw laser technique for measurements of gas velocity, temperature, pressure, density, and mass flux using NO

Cited by 45 publications

References 20 publications

Reconstruction of two-dimensional velocity distribution in scramjet by laser absorption spectroscopy tomography

Reconstruction of two-dimensional velocity distribution in scramjet by laser absorption spectroscopy tomography

Development of a Tunable Diode Laser Absorption Spectroscopy Mass-Flux Sensor for Quantifying Hydrocarbon Storage Tank Venting

Flow and Particle Diagnostics. Multi‐Parameter and Multi‐Point Measurements

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