Experimental and Numerical Studies of Radiation Emission from High-Temperature Air Behind 10 km/s Shock Waves

Honma, Hiroki; Iizuka, Hiroyuki

doi:10.4271/912025

Cited by 4 publications

(3 citation statements)

References 22 publications

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“…Notice that this secondary increase is also evident in the calculated distributions, even though the simulations include no terms to attenuate the velocity as the shock moves down the tube. The results of Honma and lizuka 19 also support the existence of a secondary rise in the intensity after the initial peak in the nonequilibrium zone. They observed secondary maxima in experimental data for shocks above 10 km/s at 0.01 mmHg.…”

Section: Intensity Tracessupporting

confidence: 72%

“…Shock-tube experiments have produced shocks in which nonequilibrium processes and radiation are important, making such experiments vital in the verification of nonequilibrium chemical and radiation models. 12 " 19 Several investigators have attempted to recreate these experiments computationally with models of varying complexity, 19 " 22 with varying degrees of success.…”

mentioning

confidence: 99%

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Viscous normal shock solutions including chemical, thermal, and radiative nonequilibrium

Mott

Gally

Carlson

1995

Journal of Thermophysics and Heat Transfer

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An existing axisymmetric body viscous shock layer code including thermochemical and thermodynamic nonequilibrium and nonequilibrium radiative gasdynamic coupling was adapted to simulate the one-dimensional flow within a shock tube. A suitable solution scheme for this case and additional radiation modeling were developed in order to compare the current computational results with experimental radiation measurements. Spectrally integrated intensity traces, time to peak radiation, and ionization distance data were generated for shocks in air with speeds between 9.5-12.6 km/s. Using the current model, the dual peak characteristics of Wilson's experimental results are reproduced without the introduction of contaminant radiation. Overall, good agreement is seen between the current calculations and the available experimental data, justifying the use of the current nonequilibrium models for engineering applications.Nomenclature A = vibrational model parameter in Eq. (7) C = mass fraction c, = constant defined by Eq.(1) c f) = constant pressure specific heat d f = ionization distance E = vibrational energy lost in dissociation e = internal energy G = vibrational energy gained in recombination h = specific enthalpy / = radiation intensity J = diffusive mass flux k = thermal conductivity MI = molecular weight of species / p = pressure ?A = universal gas constant r = coordinate perpendicular to the tube wall q,. = streamwise radiative heat flux S = radiant source function T c = electron-electronic temperature Tj = translational-rotational temperature of species / T., = vibrational temperature t = time coordinate U = diffusion velocity v = velocity w = chemical production term y = coordinate parallel to the shock tube A = downstream boundary distance 8<$ = calculated change in for one iteration absorption coefficient molecular viscosity frequency elastic electron energy exchange term density relaxation time flowfield parameter inelastic electron energy exchange term Subscripts b = boundary e = electron or electron-electronic / = species index p = peak radiation tr = translational-rotational v = vibrational v = frequency sc = preshocked value

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Section: Intensity Tracessupporting
confidence: 72%

mentioning
confidence: 99%

Viscous normal shock solutions including chemical, thermal, and radiative nonequilibrium
Mott
¹
,
Gally
²
,
Carlson
³

1995
Journal of Thermophysics and Heat Transfer
4
0
0
0
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“…3 and 4, much stronger and longer radiation is observed along the tube wall surfaces. Due to the previous conclusions by Keck et al (1959) and Honma and Iizuka (1991), the radiation was attributed to the impurities coming from Na and K. In order to inquire exactly into the constituent, the simultaneous observation is carried out along the tube wall surface. In this observation, the system of space-resolved spectral radiation, which is shown on the right hand side in Fig.…”

Section: Radiation Along the Tube Wall Surfacementioning
confidence: 99%

Observation of nonequilibrium radiation behind strong shock waves in low-density air
Morioka
¹
,
Sakurai
²
,
Maeno
³

et al. 2000
J Vis
5
0
1
0
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Nonequilibrium radiation phenomena behind strong shock waves in low-density air are observed by using a couple of CCD camera systems in a shock tube experiment. The simultaneous observation for total radiation and its spectral radiation is carried out in order to elucidate spacedependent contribution of an individual radiation spectrum to the total radiation intensity. The results are shown for the shock velocity range from 9.0 km/s to 12.1 km/s at the initial pressure 13.3 Pa. Wavelength range is selected from 300 nm to 445 nm to investigate mainly the contributions from UV radiation. It is found that the band spectra due to the molecular species N: and CN mainly contribute to the first-peak, while the spectra due to the atomic species 0+ and N mainly contribute to the formation of the second-peak. It is also found that the Balmer series in H spectra strongly contributes to the secondpeak. The radiation along the tube wall surfaces is composed ofthe same constituents as those around the tube axis as well as the spectra coming from the impurities.

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Preliminary tests for coherent anti-Stokes Raman spectroscopic measurement of radiation behind strong shock waves
Ando
¹
,
Miyazaki
²
,
Takada
³

et al. 2005
SPIE Proceedings
1
0
0
0
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Experimental and Numerical Studies of Radiation Emission from High-Temperature Air Behind 10 km/s Shock Waves

Cited by 4 publications

References 22 publications

Viscous normal shock solutions including chemical, thermal, and radiative nonequilibrium

Viscous normal shock solutions including chemical, thermal, and radiative nonequilibrium

Observation of nonequilibrium radiation behind strong shock waves in low-density air

Preliminary tests for coherent anti-Stokes Raman spectroscopic measurement of radiation behind strong shock waves

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