Flow visualization using fluorescence from locally seeded I 2 excited by an ArF excimer laser

Exton, R. J.; Balla, R. Jeffrey; Shirinzadeh, B.; Hillard, M. E.; Brauckmann, Gregory J.

doi:10.1007/s003480050296

Cited by 11 publications

(6 citation statements)

References 16 publications

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“…In addition to the aforementioned comparisons between gases, practical implications should be considered when comparing the three seed gases included in this study. Examples of the use of Kr and I 2 in PLIF experiments can be found in [47] for Kr and [48,49] for I 2 . Each of the seeded gases needs adequate gas handling equipment to ensure the safety of human operators near the wind-tunnel apparatus.…”

Section: Discussionmentioning

confidence: 99%

Investigation of Gas Seeding for Planar Laser-Induced Fluorescence in Hypersonic Boundary Layers

Arisman¹,

Johansen²,

Bathel³

et al. 2016

AIAA Journal

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Section: Discussionmentioning

confidence: 99%

Investigation of Gas Seeding for Planar Laser-Induced Fluorescence in Hypersonic Boundary Layers

Arisman¹,

Johansen²,

Bathel³

et al. 2016

AIAA Journal

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“…Examples of the use of Kr and I 2 in PLIF experiments can be found in [47] for Kr and [48,49] for I 2 .…”

Section: Discussionmentioning

confidence: 98%

Investigation of Gas Seeding for Planar Laser-Induced Fluorescence in Hypersonic Boundary Layers

Arisman

Johansen²,

Bathel

et al. 2015

AIAA Journal

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Numerical simulations of the gas-seeding strategies required for planar laser-induced fluorescence in a Mach 10 (approximately Mach 8.2 postshock) airflow were performed. The work was performed to understand and quantify the adverse effects associated with gas seeding and to assess various types of seed gas that could potentially be used in future experiments. In prior experiments, NO and NO2 were injected through a slot near the leading edge of a flatplate wedge model used in NASA Langley Research Center's 31 in. Mach 10 air tunnel facility. In this paper, nitric oxide, krypton, and iodine gases were simulated at various injection rates. Simulations showing the deflection of the velocity boundary layer for each of the cases are presented. Streamwise distributions of velocity and concentration boundary-layer thicknesses, as well as vertical distributions of velocity, temperature, and mass distributions, are presented for each of the cases. A comparison between simulated streamwise velocity profiles and experimentally obtained molecular tagging velocimetry profiles using a nitric oxide seeding strategy is performed to verify the influence of such a strategy on the boundary layer. The relative merits of the different seeding strategies are discussed. The results from a custom solver based on OpenFOAM version 2.2.1 are compared against results obtained from ANSYS® Fluent version 6.3. Nomenclature c p = specific heat at constant pressure, kJ∕kg∕K D i;j = binary diffusion coefficient, m 2 ∕s D i;m = diffusion coefficient of species i into the mixture, m 2 ∕s h i = sensible enthalpy of species i, kJ∕kg h s = sensible enthalpy, kJ∕kg I = identity matrix J i = diffusion flux of species i, kg∕m 2 ∕s Kn = Knudsen number k = thermal conductivity, W∕m∕K Ma = Mach number M i = molar mass of species i, kg∕kmol P = pressure, Pa P inf = freestream pressure, Pa P stag = stagnation pressure, Pa P w = wall pressure, Pa R = ideal gas constant, J∕K∕mol Re = Reynolds number R i = mass source of species i S h = enthalpy source, kJ∕s∕m 3 T = temperature, K T stag = stagnation temperature, K t = time, s U = velocity, m∕s U e = boundary-layer edge velocity, m∕s W z = wedge width, mm w c = species mass fraction of interest x = distance from leading edge, m x slot = length of seed slot, mm Y i = mass fraction of species i α = thermal conductivity divided by specific heat at constant pressure, kg∕m∕s β = oblique shock angle δ = boundary-layer thickness, m δ c = concentration boundary-layer thickness, m θ plate = plate angle of attack μ = viscosity, kg∕m∕s ρ = density, kg∕m 3 σ i;j = average species collision diameter, m τ = viscous stress tensor, Pa Ω d = diffusion collision integral Ω v = viscous collision integral

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“…This produces 0.66 MW cm −2 . At this level, the fluorescence signal varies linearly with the laser power density [5]. It passes through the centre of a cuvette cell (1 cm × 1 cm × 4 cm) composed of Suprasil quartz.…”

Section: The Experimental Arrangementmentioning

confidence: 99%

“…Sodium is useful for inert-gas flows but reacts explosively with water vapour and forms oxides in dry air. Exton et al [5] used local seeding of I 2 in trace amounts (<0.01 g per wind-tunnel run) to visualize a wake in a Mach 6 flow. Instantaneous planar LIF images 25 mm wide were obtained.…”

Section: Introductionmentioning

confidence: 99%

Density measurements in air by optically exciting the Cordes bands of I₂

Balla

Exton

2000

Meas. Sci. Technol.

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We describe an optical method based on laser-induced fluorescence for obtaining instantaneous measurements of density along a line in low-density air seeded with I2 . The Cordes bands of I2 (D 1 u + X 1 g + ) are excited with a tunable ArF excimer laser. Air densities in the range (0.1 - 6.5) × 1017 cm-3 are measured over 295 - 583 K using the density-dependent emission ratio of two emission bands of I2 ; the 340 nm bands and the diffuse-structured McLennan bands near 320 nm.

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Flow visualization using fluorescence from locally seeded I 2 excited by an ArF excimer laser

Cited by 11 publications

References 16 publications

Investigation of Gas Seeding for Planar Laser-Induced Fluorescence in Hypersonic Boundary Layers

Investigation of Gas Seeding for Planar Laser-Induced Fluorescence in Hypersonic Boundary Layers

Investigation of Gas Seeding for Planar Laser-Induced Fluorescence in Hypersonic Boundary Layers

Density measurements in air by optically exciting the Cordes bands of I₂

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Flow visualization using fluorescence from locally seeded I 2 excited by an ArF excimer laser

Cited by 11 publications

References 16 publications

Investigation of Gas Seeding for Planar Laser-Induced Fluorescence in Hypersonic Boundary Layers

Investigation of Gas Seeding for Planar Laser-Induced Fluorescence in Hypersonic Boundary Layers

Investigation of Gas Seeding for Planar Laser-Induced Fluorescence in Hypersonic Boundary Layers

Density measurements in air by optically exciting the Cordes bands of I2

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Density measurements in air by optically exciting the Cordes bands of I₂