Raman measurement of mixing and finite-rate chemistry in a supersonic hydrogen-air diffusion flame

Cheng, T. S.; Wehrmeyer, Joseph A.; Pitz, Robert W.; Jarrett, O.; Northam, G. B.

doi:10.1016/0010-2180(94)90087-6

Cited by 132 publications

(97 citation statements)

References 16 publications

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“…1 -is imposed at the supersonic inlet of the simulation located at x/D=0.85. Homogeneous isotropic turbulence is then superimposed in the vitiated air coflow, with a rms velocity of 300 m/s, consistently with the 20% fluctuations in velocity at the jet exit reported in the experiment [16].…”

Section: Numerical Set-upsupporting

confidence: 76%

“…The supersonic burner (SSB) of the NASA Langley Research Center [16] sketched in Fig. 1 and with operating conditions given in Table 1, produces an axy-symmetric flame from a sonic pure hydrogen cold jet surrounded by a largely supersonic (Mach 2) jet of hot products generated by a lean combustor.…”

Section: Description Of the Supersonic Flamementioning

confidence: 99%

“…Massive convection leads to a large induction zone, preceding the flame stabilization area, about 6 cm from the nozzle exit, or 25 D (D=2.36 mm, is the diameter of the inner hydrogen jet). The work of Cheng et al [16] with the SSB provides accurate experimental data on the dynamics, the mixing and the combustion conditions of this supersonic lifted flame. Through combining ultraviolet spontaneous vibrational Raman scattering and laser-induced predissociative fluorescence techniques, they obtained simultaneous instantaneous measurements for temperature and species concentrations (main species and OH radical).…”

Section: Description Of the Supersonic Flamementioning

confidence: 99%

“…AVBP is an un- [16]. structured parallel compressible solver designed for Large Eddy Simulation (LES) or Direct Numerical Simulation (DNS) of combustion systems.…”

Section: Numerical Set-upmentioning

confidence: 99%

“…The boundary conditions have proven to be one of the most sensitive elements in simulating this flame. The experiments in [16] provide detailed data on the fluid mechanical scales and on the flow composition at x/D=0.85, a very short distance from the nozzle exit compared to the 25D experimental flame stabilization lift-off height. A set of velocity, temperature, pressure and main species concentrations profiles -consistent with the experimental data and the nominal flow rates of the burner given in Tab.…”

Section: Numerical Set-upmentioning

confidence: 99%

See 4 more Smart Citations

Simulation of a supersonic hydrogen–air autoignition-stabilized flame using reduced chemistry

Boivin

Dauptain

Jiménez

et al. 2012

Combustion and Flame

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A three-step mechanism for H 2 -air combustion (Boivin et al., Proc. Comb. Inst. 33, 2010) was recently designed to reproduce both autoignition and flame propagation, essential in lifted flame stabilization. To study the implications of the use of this reduced chemistry in the context of a turbulent flame simulation, this mechanism has been implemented in a compressible explicit code and applied to the simulation of a supersonic lifted co-flowing hydrogen-air flame. Results are compared with experimental measurements (Cheng et al. C&F 1994) and simulations using detailed chemistry, showing that the reduced chemistry is very accurate. A new explicit diagnostic to readily identify autoignition regions in the post-processing of a turbulent hydrogen flame simulation is also proposed, based on variables introduced in the development of the reduced chemical mechanism.

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Section: Numerical Set-upsupporting

confidence: 76%

Section: Description Of the Supersonic Flamementioning

confidence: 99%

Section: Description Of the Supersonic Flamementioning

confidence: 99%

“…AVBP is an un- [16]. structured parallel compressible solver designed for Large Eddy Simulation (LES) or Direct Numerical Simulation (DNS) of combustion systems.…”

Section: Numerical Set-upmentioning

confidence: 99%

Section: Numerical Set-upmentioning

confidence: 99%

See 3 more Smart Citations

Simulation of a supersonic hydrogen–air autoignition-stabilized flame using reduced chemistry

Boivin

Dauptain

Jiménez

et al. 2012

Combustion and Flame

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One-dimensional imaging of H2 densities and of temperatures via rotational Raman scattering of narrow-band, 248 nm, laser light

Rothe

Reck

1997

J. Raman Spectrosc.

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It is demonstrated that the well known rotational Raman spectrum of H2 can be used to find the relative densities of hydrogen and the gas temperature as a function of position. A line‐shaped beam from a tunable excimer laser intersects H2–air flames. Scattered light is acquired with an imaging spectrograph. This produces both Stokes and anti‐Stokes spectra. By adjusting the laser beam’s polarization, the interfering Rayleigh intensity is sufficiently reduced without the use of a filter. The temperature measurements can be from below room temperature to about 1200 K. The method also works at temperatures >1200 K, but the use of vibrational Raman spectroscopy is probably better there. Also shown is an image that has simultaneously acquired, spatially resolved spectra from rotational Raman, vibrational Raman and laser‐induced fluorescence. Such combined information might be used to diagnose a gaeous system in some detail. © 1997 John Wiley & Sons, Ltd.

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Influence of reaction mechanisms, grid spacing, and inflow conditions on the numerical simulation of lifted supersonic flames

Gerlinger

Nold²,

Aigner³

2009

Numerical Methods in Fluids

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SUMMARYThe simulation of supersonic combustion requires finite-rate chemistry because chemical and fluid mechanical time scales may be of the same order of magnitude. The size of the chosen reaction mechanism (number of species and reactions involved) has a strong influence on the computational time and thus should be chosen carefully. This paper investigates several hydrogen/air reaction mechanisms frequently used in supersonic combustion. It is shown that at low flight Mach numbers of a supersonic combustion ramjet (scramjet), some kinetic schemes can cause highly erroneous results. Moreover, extremely fine computational grids are required in the lift-off region of supersonic flames to obtain grid-independent solutions. The fully turbulent Mach 2 combustion experiment of Cheng et al. (Comb. Flame 1994; 99: 157-173) is chosen to investigate the influences of different reaction mechanisms, grid spacing, and inflow conditions (contaminations caused by precombustion). A detailed analysis of the experiment will be given and errors of previous simulations are identified. Thus, the paper provides important information for an accurate simulation of the Cheng et al. experiment. The importance of this experiment results from the fact that it is the only supersonic combustion test case where temperature and species fluctuations have been measured simultaneously. Such data are needed for the validation of probability density function methods.

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Raman measurement of mixing and finite-rate chemistry in a supersonic hydrogen-air diffusion flame

Cited by 132 publications

References 16 publications

Simulation of a supersonic hydrogen–air autoignition-stabilized flame using reduced chemistry

Simulation of a supersonic hydrogen–air autoignition-stabilized flame using reduced chemistry

One-dimensional imaging of H2 densities and of temperatures via rotational Raman scattering of narrow-band, 248 nm, laser light

Influence of reaction mechanisms, grid spacing, and inflow conditions on the numerical simulation of lifted supersonic flames

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