Two-component Doppler-shift fluorescence velocimetry applied to a generic planetary entry probe model

Hruschka, R.; O’Byrne, Sean; Kleine, H.

doi:10.1007/s00348-009-0794-3

Cited by 19 publications

(5 citation statements)

References 45 publications

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“…[11][12][13][14][15] The Doppler effect shifts the location of the spectral line center relative to the static vacuum center if the flow has a velocity component in the direction of the laser. This Doppler shift, and thus the flow velocity, can be determined from NO PLIF imaging in a variety of ways, including both fixed-and tunable-frequency methods.…”

Section: E Doppler Velocimetry For Radial Velocity Measurementsmentioning

confidence: 99%

Nitric Oxide PLIF Measurements in the Hypersonic Materials Environmental Test System (HYMETS)

Inman

Bathel

Johansen

et al. 2011

49th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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A nonintrusive laser-based measurement system has been applied for the first time in the HYMETS (Hypersonic Materials Environmental Test System) 400 kW arc-heated wind tunnel at NASA Langley Research Center. Planar laser-induced fluorescence of naturally occurring nitric oxide (NO) has been used to obtain instantaneous flow visualization images, and to make both radial and axial velocity measurements. Results are presented at selected facility run conditions, including some in simulated Earth atmosphere (75% nitrogen, 20% oxygen, 5% argon) and others in simulated Martian atmosphere (71% carbon dioxide, 24% nitrogen, 5% argon), for bulk enthalpies ranging from 6.5 MJ/kg to 18.4 MJ/kg. Flow visualization images reveal the presence of large scale unsteady flow structures, and indicate nitric oxide fluorescence signal over more than 70% of the core flow for bulk enthalpies below about 11 MJ/kg, but over less than 10% of the core flow for bulk enthalpies above about 16 MJ/kg. Axial velocimetry was performed using molecular tagging velocimetry (MTV). Axial velocities of about 3 km/s were measured along the centerline. Radial velocimetry was performed by scanning the wavelength of the narrowband laser and analyzing the resulting Doppler shift. Radial velocities of ±0.5km/s were measured.

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Section: E Doppler Velocimetry For Radial Velocity Measurementsmentioning

confidence: 99%

Nitric Oxide PLIF Measurements in the Hypersonic Materials Environmental Test System (HYMETS)

Inman

Bathel

Johansen

et al. 2011

49th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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“…Therefore, an error in the predicted chemical composition of the freestream is expected, the magnitude of which is unknown. The mole fractions over the range of test conditions (1)(2)(3)(4)(5)(6)(7)(8) were computed from equilibrium to be 0.21 < χ O < 0.28 and 0.0036 < χ NO < 0.04, respectively. Note that χ O increases with increasing bulk enthalpy, whereas χ NO decreases with increasing bulk enthalpy.…”

Section: A Equilibrium Calculationsmentioning

confidence: 99%

“…Therefore, a large number of runs become necessary to resolve a single transition. For example, Hruschka et al performed two-component Dopplershift nitric-oxide (NO) PLIF velocimetry in the T-ADFA free-piston shock tunnel running at a stagnation enthalpy of 3.8 MJ∕kg and a freestream Mach number of 10 [3]. In these tests, 29 tunnel runs were required to resolve the R R 22 (14) transition used to extract the radialvelocity distribution in the wake of a capsule model.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous Nitric Oxide/Atomic Oxygen Laser-Induced Fluorescence in an Arcjet Facility

Johansen¹,

Lincoln²,

Bathel³

et al. 2016

Journal of Thermophysics and Heat Transfer

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Simultaneous nitric-oxide and atomic-oxygen laser-induced-fluorescence experiments were performed in the Hypersonic Materials Environmental Test System facility at the NASA Langley Research Center. The data serve as an experimental database for validation for chemical and thermal nonequilibrium models used in hypersonic flows. Measurements were taken over a wide range of stagnation enthalpies (6.7−18.5 MJ∕kg) using an Earth atmosphere simulant with a composition of 75% nitrogen, 20% oxygen, and 5% argon (by volume). These are the first simultaneous measurements of nitric-oxide and atomic-oxygen laser-induced fluorescence to be reported in literature for the Hypersonic Materials Environmental Test System facility. The maximum atomic-oxygen laser-inducedfluorescence mean signal intensity was observed at a stagnation enthalpy of approximately 12 MJ∕kg, whereas the maximum nitric-oxide laser-induced-fluorescence mean signal intensity was observed at a stagnation enthalpy of 6.7 MJ∕kg. The experimental results were compared to a fluorescence model that assumes equilibrium conditions in the plenum and frozen chemistry in an isentropic nozzle expansion (Mach 5). The equilibrium calculations were performed using CANTERA v2.1.1 with 16 species. The fluorescence model captured the correlation in mean atomicoxygen laser-induced-fluorescence and nitric-oxide laser-induced-fluorescence signal intensities over a large range of stagnation enthalpies tested. The agreement between equilibrium calculations and the experimental laser-induced fluorescence signals was better for nitric oxide than atomic oxygen. Very weak correlations between single-shot atomic-oxygen laser-induced-fluorescence and nitric-oxide laser-induced-fluorescence intensities were observed in the experiments at all of the stagnation enthalpy conditions. It was found that the overall magnitude of nitric-oxide laser-induced-fluorescence fluctuations was much larger than atomic-oxygen laser-induced-fluorescence fluctuations.

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“…NO PLIF has previously been used in high-enthalpy shock tunnel facilities at numerous laboratories, though RCS jet flows have not been investigated in these facilities to our knowledge. [21][22][23][24] The laser system used in the current work operates at 10 Hz allowing only one image per tunnel run. However, the current system produces pulses with 10x higher laser energy than the high speed system previously used at CUBRC, allowing larger (6‖x6‖) field of view (FOV) images to be captured with a good signal-to-noise ratio.…”

Section: Figure 1: Layout Of the Mpcv Rcs3mentioning

confidence: 99%

NO PLIF Visualizations of the Orion Capsule in LENS-I

Combs

Clemens

Danehy

et al. 2013

51st AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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Two-component Doppler-shift fluorescence velocimetry applied to a generic planetary entry probe model

Cited by 19 publications

References 45 publications

Nitric Oxide PLIF Measurements in the Hypersonic Materials Environmental Test System (HYMETS)

Nitric Oxide PLIF Measurements in the Hypersonic Materials Environmental Test System (HYMETS)

Simultaneous Nitric Oxide/Atomic Oxygen Laser-Induced Fluorescence in an Arcjet Facility

NO PLIF Visualizations of the Orion Capsule in LENS-I

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