Combustion exhaust measurements of nitric oxide with an ultraviolet diode-laser-based absorption sensor

Anderson, Thomas N.; Lucht, Robert P.; Barron-Jimenez, Rodolfo; Hanna, Sherif F.; Caton, Jerald A.; Walther, Thomas; Roy, Sukesh; Brown, Michael S.; Gord, James R.; Critchley, Ian; Flamand, Luis

doi:10.1364/ao.44.001491

Cited by 24 publications

(19 citation statements)

References 30 publications

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“…The collisional linewidth is proportional to 1= T p ; thus, we can obtain good approximation of the pressure using an initial guess value of temperature. The LIF line shapes were fit using a computer program described by Anderson et al [37] to obtain pressure and temperature values. The computer program includes a detailed spectroscopic model for NO, and a Voigt profile is used for the line shape function.…”

Section: Resultsmentioning

confidence: 99%

Pressure, Temperature and Velocity Measurements in Underexpanded Free Jets using Laser-Induced Fluorescence Imaging

et al. 2009

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We report measurements of pressure, temperature, and velocity in an underexpanded jet using planar laserinduced fluorescence of nitric oxide. Ultraviolet transitions near 44; 097:5 cm 1 in the A-X (0,0) system of nitric oxide were excited using narrow linewidth laser radiation generated from an optical parametric system, injection seeded using a distributed feedback diode laser. Planar laser-induced fluorescence images with excellent spatial resolution and signal-to-noise ratio were acquired by tuning the frequency of the laser radiation over the nitric oxide absorption line. The images were corrected on a shot-to-shot basis for fluctuations in the laser spatial profile. Line shapes constructed from the corrected planar laser-induced fluorescence images were used to determine pressure and temperature values along the centerline of the jet. Good agreement between laser-induced fluorescence and previously reported N 2 coherent anti-Stokes Raman scattering measurements was observed. The laser-induced fluorescence measurements also compared well with calculations of pressure and temperature using computational fluid dynamics codes. Velocity was measured in supersonic regions of the flowfield on the basis of the Doppler shift in the nitric oxide absorption lines. Planar laser-induced fluorescence images were acquired using laser sheets propagating at 90 and 45 degrees with respect to the flow direction; velocity was determined from the frequency shift of the absorption lines for these two shifts. The laser-induced fluorescence technique can potentially be applied to obtain instantaneous measurements of thermodynamic properties and multiple velocity components in high-speed turbulent flows.

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Section: Resultsmentioning

confidence: 99%

Pressure, Temperature and Velocity Measurements in Underexpanded Free Jets using Laser-Induced Fluorescence Imaging

et al. 2009

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“…To address this, diode-laser-absorption-based high-speed measurement systems have been used to perform multikilohertz measurements of gas properties in internal combustion engines [10][11][12][13][14][15], though primarily in single-cylinder engines. In addition, diode-laser-based strategies have also been used in a variety of other combustion devices including flat flame burners [16,17], scramjet combustors [18], and gas turbine engines [19,20]. Absorption spectroscopy provides a path-averaged and quantitative measure of gas properties (temperature, pressure, and concentration) in the region of interest.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous high-speed gas property measurements at the exhaust gas recirculation cooler exit and at the turbocharger inlet of a multicylinder diesel engine using diode-laser-absorption spectroscopy

et al. 2015

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A diode-laser-absorption-spectroscopy-based sensor system was used to perform high-speed (100 Hz to 5 kHz) measurements of gas properties (temperature, pressure, and H(2)O vapor concentration) at the turbocharger inlet and at the exhaust gas recirculation (EGR) cooler exit of a diesel engine. An earlier version of this system was previously used for high-speed measurements of gas temperature and H(2)O vapor concentration in the intake manifold of the diesel engine. A 1387.2 N m tunable distributed feedback diode laser was used to scan across multiple H(2)O absorption transitions, and the direct absorption signal was recorded using a high-speed data acquisition system. Compact optical connectors were designed to conduct simultaneous measurements in the intake manifold, the EGR cooler exit, and the turbocharger inlet of the engine. For measurements at the turbocharger inlet, these custom optical connectors survived gas temperatures as high as 800 K using a simple and passive arrangement in which the temperature-sensitive components were protected from high temperatures using ceramic insulators. This arrangement reduced system cost and complexity by eliminating the need for any active water or oil cooling. Diode-laser measurements performed during steady-state engine operation were within 5% of the thermocouple and pressure sensor measurements, and within 10% of the H(2)O concentration values derived from the CO(2) gas analyzer measurements. Measurements were also performed in the engine during transient events. In one such transient event, where a step change in fueling was introduced, the diode-laser sensor was able to capture the 30 ms change in the gas properties; the thermocouple, on the other hand, required 7.4 s to accurately reflect the change in gas conditions, while the gas analyzer required nearly 600 ms. To the best of our knowledge, this is the first implementation of such a simple and passive arrangement of high-temperature optical connectors as well as the first documented application of diode-laser absorption for high-speed gas dynamics measurements in the turbocharger inlet and EGR cooler exit of a diesel engine.

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“…Laser absorption spectroscopy, on the other hand, provides fast, sensitive and non-intrusive sensing of flow composition and temperature. 15–34 Although the measured quantities are path-averaged, absorption spectroscopy is species specific and quantitative, making it highly suitable for measurements outside the engine cylinder where the gas conditions are expected to be near-uniform along the laser path. Therefore, laser absorption has been widely used in harsh environments to measure species including NO and OH in gas turbine combustors; 16,17 O 2 , CO 2 and CH 4 in gas-fired power plants; 18 potassium in coal combustion systems 19 and water vapor in various combustion devices.…”

Section: Introductionmentioning

confidence: 99%

High-speed diode laser measurements of temperature and water vapor concentration in the intake manifold of a diesel engine

Jatana

Naik

Shaver

et al. 2014

International Journal of Engine Research

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A diode laser–based sensor system, utilizing absorption spectroscopy, has been developed to provide high-speed (5 kHz) simultaneous measurements of temperature and water vapor concentration in the intake manifold of a diesel engine. A fiber-coupled 1.38 µm diode laser was used to probe absorption transitions of water vapor for the high-speed gas temperature and water vapor concentration measurements. Water vapor readily absorbs in the near-infrared region, and distributed feedback diode lasers as well as optics for near-infrared region are readily available because of their use in telecommunications. Fresh charge and combustion products are the only sources of water vapor in an engine’s gas exchange path; therefore, water vapor concentration at various locations in the intake manifold is a useful measure of the recirculated exhaust gas distribution in the intake manifold. Measurements were performed on a six-cylinder Cummins diesel engine using compact fiber optic–coupled connectors. The chosen water vapor absorption transitions provided good absorption strength even without exhaust gas recirculation and water vapor concentration of as low as 0.7 vol.% could be measured with a signal-to-noise ratio of ∼35 leading to very good spectral fits. The sensor output was within 2% of the thermocouple readings and within 10% of the water vapor concentration derived from mean CO2 analyzer measurements for steady-state engine operation. For transient engine operation, the time response of the diode laser sensor was shown to be vastly superior to that of the installed thermocouple and the gas analyzer system.

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Combustion exhaust measurements of nitric oxide with an ultraviolet diode-laser-based absorption sensor

Cited by 24 publications

References 30 publications

Pressure, Temperature and Velocity Measurements in Underexpanded Free Jets using Laser-Induced Fluorescence Imaging

Pressure, Temperature and Velocity Measurements in Underexpanded Free Jets using Laser-Induced Fluorescence Imaging

Simultaneous high-speed gas property measurements at the exhaust gas recirculation cooler exit and at the turbocharger inlet of a multicylinder diesel engine using diode-laser-absorption spectroscopy

High-speed diode laser measurements of temperature and water vapor concentration in the intake manifold of a diesel engine

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