Properties of Laminar Premixed CO/H/Air Flames at Various Pressures

Hassan, M. I.; Аунг, К.; Faeth, G. M.

doi:10.2514/2.5154

Cited by 135 publications

(48 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This could be attributed to the higher hydrogen content in PG3. This behaviour was also observed by Hassan et al [10]; with an increase of H 2 fraction (by volume) from 3% to 50% in a binary fuel mixture of H 2 -CO, the neutral stability shifts from φ ≈ 1.1 to 1.6, showing the effect of hydrogen content in fuel on preferential diffusion stability.…”

Section: Burning Velocities and Markstein Numbers Of Producer Gas-airsupporting

confidence: 80%

“…The thermal diffusion effect was included in these computations [14]. Predictions of unstretched laminar burning velocities for these mixtures with RUN1DL using the Warnatz C1 mechanism for spherically expanding flames are plotted in Figure 2 and compared with spherically expanding flame measurements by Hassan et al [10], McLean et al [20], and Sun et al [21] and those obtained with PREMIX using GRI-MECH Hassan et al [10] McLean et al [20] Sun et al [21] RUN1DL-C1 chemistry PREMIX-GRIMECH H 2 50%-CO 50% H 2 5%-CO 95% 3.0 for freely propagating planar flames. The comparisons with experiments are quite good and RUN1DL predicts peak burning velocities at the same equivalence ratios as in the experiments.…”

Section: Assessment Of Suitability Of Reaction Mechanisms For Presentmentioning

confidence: 99%

“…Faeth et al [9][10][11][12][13] measured laminar burning velocity along with stretch correction and Markstein numbers to understand stability using a schlieren apparatus and high-speed photography for constant pressure spherical outwardly propagating flames of methane, hydrogen, and hydrogen/carbon monoxide with air. They also computed the laminar burning velocity using RUN1DL [14] and PREMIX [6] and discussed the stretch/preferential diffusion interactions based on the computed flame structures.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effect of Hydrogen Content and Dilution on Laminar Burning Velocity and Stability Characteristics of Producer Gas-Air Mixtures

Velamati

Ravi

Ray

2008

International Journal of Reacting Systems

View full text Add to dashboard Cite

Recommended by Lea-Der ChenProducer gas is one of the promising alternative fuels with typical constituents of H 2 , CO, CH 4 , N 2 , and CO 2 . The laminar burning velocity of producer gas was computed for a wide range of operating conditions. Flame stability due to preferential diffusional effects was also investigated. Computations were carried out for spherical outwardly propagating flames and planar flames. Different reaction mechanisms were assessed for the prediction of laminar burning velocities of CH 4 , H 2 , H 2 -CO, and CO-CH 4 and results showed that the Warnatz reaction mechanism with C1 chemistry was the smallest among the tested mechanisms with reasonably accurate predictions for all fuels at 1 bar, 300 K. To study the effect of variation in the producer gas composition, each of the fuel constituents in ternary CH 4 -H 2 -CO mixtures was varied between 0 to 48%, while keeping diluents fixed at 10% CO 2 and 42% N 2 by volume. Peak burning velocity shifted from φ = 1.6 to 1.1 as the combined volumetric percentage of hydrogen and CO varied from 48% to 0%. Unstable flames due to preferential diffusion effects were observed for lean mixtures of fuel with high hydrogen content. The present results indicate that H 2 has a strong influence on the combustion of producer gas.

show abstract

Section: Burning Velocities and Markstein Numbers Of Producer Gas-airsupporting

confidence: 80%

Section: Assessment Of Suitability Of Reaction Mechanisms For Presentmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of Hydrogen Content and Dilution on Laminar Burning Velocity and Stability Characteristics of Producer Gas-Air Mixtures

Velamati

Ravi

Ray

2008

International Journal of Reacting Systems

View full text Add to dashboard Cite

show abstract

“…Groff [4] first measured spherical flame speeds at high pressures, up to 5 atm, by directly imaging the propagating flame front and also through pressure measurements. Lately, Taylor and coworkers [5][6][7] and Faeth and coworkers [8][9][10][11][12][13] determined val-0 s u ues for various fuel compositions and pressures through systematic subtraction of stretch effects using similar imaging techniques. The values so de-0 s u termined, with different stretch-compensated relations, are in reasonably good agreement with each other, as well as with computational calculations and the data from counterflow experiments.…”

Section: Introductionmentioning

confidence: 99%

Morphology and burning rates of expanding spherical flames in H2/O2/inert mixtures up to 60 atmospheres

Tse

Zhu

Law

2000

Proceedings of the Combustion Institute

323

143

View full text Add to dashboard Cite

Recognizing that previous experimental studies on constant-pressure, outwardly propagating, spherical flames with imaging capability were limited to pressures less than about 5 atm, and that pressures within internal combustion engines are substantially higher, a novel experimental apparatus was designed to extend the environmental pressure to 60 atm. Results substantiate previous observations of the propensity of cell formation over the flame surface due to hydrodynamic and diffusive-thermal instabilities and provide convincing evidence that wrinkled flame is the preferred mode of propagation in hydrogen/air mixtures in environments with pressures above only a few atmospheres. It is further shown that, by using helium as the diluent, and by reducing the oxygen concentration of the combustible, diffusional-thermal instability can be mostly suppressed and the hydrodynamic instability delayed. Stretch-free laminar flame speeds were subsequently determined for such smooth flames up to 20 atm and were compared with the calculated values, allowing for detailed chemistry and transport.

show abstract

“…Figure 2 shows the measured laminar burning velocity of H 2 /CO/air mixtures compared with those of previous studies [42,[47][48][49][50][51][52]; all the data were measured with a spherically propagating flame at P u = 0.1 MPa and all data are in good agreement. This proves the correctness of the data obtained in this investigation.…”

Section: System Validation and Laminar Burning Velocitymentioning

confidence: 61%

Research on Cellular Instabilities of Lean Premixed Syngas Flames under Various Hydrogen Fractions Using a Constant Volume Vessel

Sun

et al. 2014

Energies

View full text Add to dashboard Cite

An experimental study of the intrinsic instabilities of H 2 /CO lean (φ = 0.4 to φ = 1.0) premixed flames at different hydrogen fractions ranging from 0% to 100% at elevated pressure and room temperature was performed in a constant volume vessel using a Schlieren system. The unstretched laminar burning velocities were compared with data from the previous literature and simulated results. The results indicate that excellent agreements are obtained. The cellular instabilities of syngas-air flames were discussed and critical flame radii were measured. When hydrogen fractions are above 50%, the flame tends to be more stable as the equivalence ratio increases; however, the instability increases for flames of lower hydrogen fractions. For the premixed syngas flame with hydrogen fractions greater than 50%, the decline in cellular instabilities induced by the increase in equivalence ratio can be attributed to a reduction of diffusive-thermal instabilities rather than increased hydrodynamic instabilities. For premixed syngas flames with hydrogen fractions lower than 50%, as the equivalence ratio increases, the cellular instabilities become more evident because the enhanced hydrodynamic instabilities become the dominant effect. For premixed syngas flames, the enhancement of cellular instabilities induced by the increase in hydrogen fraction is the result of both increasing diffusive-thermal and hydrodynamic instabilities.

show abstract

Properties of Laminar Premixed CO/H/Air Flames at Various Pressures

Cited by 135 publications

References 15 publications

Effect of Hydrogen Content and Dilution on Laminar Burning Velocity and Stability Characteristics of Producer Gas-Air Mixtures

Effect of Hydrogen Content and Dilution on Laminar Burning Velocity and Stability Characteristics of Producer Gas-Air Mixtures

Morphology and burning rates of expanding spherical flames in H2/O2/inert mixtures up to 60 atmospheres

Research on Cellular Instabilities of Lean Premixed Syngas Flames under Various Hydrogen Fractions Using a Constant Volume Vessel

Contact Info

Product

Resources

About