Shock tunnel flow visualization using planar laser-induced fluorescence imaging of NO and OH

Palmer, Jennifer L.; Hanson, Ronald K.

doi:10.1007/bf01413873

Cited by 21 publications

(3 citation statements)

References 22 publications

(30 reference statements)

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“…It is thus the standard technique for NO detection in flames, and it is the only technique sensitive to cold NO, e.g., in flow-field diagnostics. 39,40 Highpressure applications include small-scale laboratory flames and gasoline and Diesel IC engines with different signal collection strategies varying from narrowband detection ͓3-nm bandpass detecting A-X͑0, 1͒ emission 41 ͔ to broadband detection integrating over several vibrational bands ͓for example, Dec and Canaan: A-X͑0, 1͒ to ͑0, 4͒ 42 ͔.…”

Section: A-x͑0 0͒ Excitationmentioning

confidence: 99%

Strategies for laser-induced fluorescence detection of nitric oxide in high-pressure flames III Comparison of A–X excitation schemes

et al. 2003

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Laser-induced fluorescence (LIF) has proven a reliable technique for nitric oxide (NO) diagnostics in practical combustion systems. However, a wide variety of different excitation and detection strategies are proposed in the literature without giving clear guidelines of which strategies to use for a particular diagnostic situation. We give a brief review of the high-pressure NO LIF diagnostics literature and compare strategies for exciting selected transitions in the A-X(0, 0), (0, 1), and (0, 2) bands using a different detection bandpass. The strategies are compared in terms of NO LIF signal strength, attenuation of laser and signal light in the hot combustion gases, signal selectivity against LIF interference from O2 and CO2, and temperature and pressure sensitivity of the LIF signal. The discussion is based on spectroscopic measurements in laminar premixed methane-air flames at pressures between 1 and 60 bars and on NO and O2 LIF spectral simulations.

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Section: A-x͑0 0͒ Excitationmentioning

confidence: 99%

Strategies for laser-induced fluorescence detection of nitric oxide in high-pressure flames III Comparison of A–X excitation schemes

et al. 2003

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“…The tracer selection is more crucially dependent upon the quantity to be measured and the relevant photophysical characteristics of the tracer. Most of the previous work on PLIF imaging of supersonic jet uses diatomic molecules as tracers, for example NO and OH (Arnette et al 1993;Rossmann et al 2001;Hsu et al 2009;Lachney and Clemens 1998;Palmer and Hanson 1995). One of the major difficulties in using diatomic molecules is their narrow absorption wavelength range.…”

Section: Introductionmentioning

confidence: 99%

Acetone planar laser-induced fluorescence for supersonic flow visualization in air and nitrogen jet

Shelar

Hegde

et al. 2014

Int J Mech Mater Eng

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Background: Laser based flow visualization techniques are indispensable tools for flow visualization in fluid dynamics and combustion diagnostics. Among these, PLIF is very popular because of its capability to give quantitative information about the flow. This paper reports the acetone tracer-based PLIF imaging of supersonic jet with air and nitrogen as bath gases. Methods: The tracer was seeded in the flow by purging bath gas through the liquid acetone at ambient temperature. Planar laser sheet from frequency quadrupled, Q-switched, Nd:YAG laser (266 nm) was used as an excitation source. Emitted PLIF images of a jet flow field were recorded on ICCD camera. Results: In this study, the dependence of PLIF images intensity on oxygen by comparing nitrogen jet with air in supersonic regime was presented. A lower temperature at the exit of the supersonic jet condenses the tracer which in turn forms droplets. Conclusions: There was a significant decrease in the PLIF image intensity in the case of air. This may be attributed to the oxygen present in the air. It is shown that image adding and Gaussian image processing of PLIF images for steadystate jet improve the quality of images.

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“…Planar laser-induced fluorescence (PLIF) is a powerful flow visualization technique that provides a means of making non-intrusive measurements with sub-millimeter spatial resolution and flow-stopping temporal resolution in many of these challenging testing regimes. [7] II. PLIF MEASUREMENT SYSTEM…”

Section: Introductionmentioning

confidence: 99%

Fluorescence Imaging Study of Transition in Underexpanded Free Jets

Wilkes

Danehy²,

Nowak³

ICIASF 2005 RecordInternational Congress onInstrumentation in AerospaceSimulation Facilities

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Abstract-Planar laser-induced fluorescence (PLIF) is demonstrated to be a valuable tool for studying the onset of transition to turbulence. For this study, we have used PLIF of nitric oxide (NO) to image underexpanded axisymmetric free jets issuing into a low-pressure chamber through a smooth converging nozzle with a sonic orifice. Flows were studied over a range of Reynolds numbers and nozzle-exit-to-ambient pressure ratios with the aim of empirically determining criteria governing the onset of turbulence. We have developed an image processing technique, involving calculation of the standard deviation of the intensity in PLIF images, in order to aid in the identification of turbulence. We have used the resulting images to identify laminar, transitional and turbulent flow regimes. Jet scaling parameters were used to define a rescaled Reynolds number that incorporates the influence of a varying pressure ratio. An empirical correlation was found between transition length and this rescaled Reynolds number for highly underexpanded jets.

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Shock tunnel flow visualization using planar laser-induced fluorescence imaging of NO and OH

Cited by 21 publications

References 22 publications

Strategies for laser-induced fluorescence detection of nitric oxide in high-pressure flames III Comparison of A–X excitation schemes

Strategies for laser-induced fluorescence detection of nitric oxide in high-pressure flames III Comparison of A–X excitation schemes

Acetone planar laser-induced fluorescence for supersonic flow visualization in air and nitrogen jet

Fluorescence Imaging Study of Transition in Underexpanded Free Jets

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