Abstract
We report investigations of degenerate four-wave mixing (DFWM) in the NO A2Σ+←X2Π(ν′=0←ν″=0) band for combustion-diagnostic applications. We have performed high-resolution measurements of DFWM line shapes and intensities with varying foreign-gas pressures and compared the results to simple models. In addition, we have demonstrated the ability to detect flame-generated NO using DFWM, and have tested predictive capabilities of the models by comparing flame spectra to model spectra. Measurements were obtained using a single-mode laser (0.004 cm-1 bandwidth) and a widely tunable multi-mode laser operating near 226 nm. We found that a two-level, moving-absorber model of Abrams et al. [Optical Phase Conjugation, (R. A. Fisher, Ed.), p. 234, Academic Press, 1983] gave an excellent description of DFWM line shapes of NO broadened by He, over a range of pressures spanning the Doppler and collisional broadening regimes. We also investigated the dependence of peak DFWM intensities on foreign-gas pressure, confirming a theoretically predicted rapid decrease in DFWM signal intensities with increasing foreign-gas pressure. However, observed intensities decreased more slowly than predicted. In addition, we observed a greatly reduced pressure dependence when the DFWM signals were strongly saturated. DFWM spectra from thermally generated NO in an H2/O2/N2 diffusion flame were obtained with high signal-to-noise ratio and with relatively low saturation. A comparison of a flame spectrum with a model simulation exhibited excellent agreement. The model used the moving-absorber line-shape model and NO spectral data from the literature, and had no adjusted parameters.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1653-1659 |
| Number of pages | 7 |
| Journal | Symposium (International) on Combustion |
| Volume | 24 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 1 1992 |
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All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Fuel Technology
- Energy Engineering and Power Technology
- Mechanical Engineering
- Physical and Theoretical Chemistry
- Fluid Flow and Transfer Processes
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High-resolution investigation of degenerate four-wave mixing in the γ(0, 0) band of nitric oxide. / Vander Wal, Randy Lee; Farrow, Roger L.; Rakestraw, David J.
In: Symposium (International) on Combustion, Vol. 24, No. 1, 01.01.1992, p. 1653-1659.Research output: Contribution to journal › Article
TY - JOUR
T1 - High-resolution investigation of degenerate four-wave mixing in the γ(0, 0) band of nitric oxide
AU - Vander Wal, Randy Lee
AU - Farrow, Roger L.
AU - Rakestraw, David J.
PY - 1992/1/1
Y1 - 1992/1/1
N2 - We report investigations of degenerate four-wave mixing (DFWM) in the NO A2Σ+←X2Π(ν′=0←ν″=0) band for combustion-diagnostic applications. We have performed high-resolution measurements of DFWM line shapes and intensities with varying foreign-gas pressures and compared the results to simple models. In addition, we have demonstrated the ability to detect flame-generated NO using DFWM, and have tested predictive capabilities of the models by comparing flame spectra to model spectra. Measurements were obtained using a single-mode laser (0.004 cm-1 bandwidth) and a widely tunable multi-mode laser operating near 226 nm. We found that a two-level, moving-absorber model of Abrams et al. [Optical Phase Conjugation, (R. A. Fisher, Ed.), p. 234, Academic Press, 1983] gave an excellent description of DFWM line shapes of NO broadened by He, over a range of pressures spanning the Doppler and collisional broadening regimes. We also investigated the dependence of peak DFWM intensities on foreign-gas pressure, confirming a theoretically predicted rapid decrease in DFWM signal intensities with increasing foreign-gas pressure. However, observed intensities decreased more slowly than predicted. In addition, we observed a greatly reduced pressure dependence when the DFWM signals were strongly saturated. DFWM spectra from thermally generated NO in an H2/O2/N2 diffusion flame were obtained with high signal-to-noise ratio and with relatively low saturation. A comparison of a flame spectrum with a model simulation exhibited excellent agreement. The model used the moving-absorber line-shape model and NO spectral data from the literature, and had no adjusted parameters.
AB - We report investigations of degenerate four-wave mixing (DFWM) in the NO A2Σ+←X2Π(ν′=0←ν″=0) band for combustion-diagnostic applications. We have performed high-resolution measurements of DFWM line shapes and intensities with varying foreign-gas pressures and compared the results to simple models. In addition, we have demonstrated the ability to detect flame-generated NO using DFWM, and have tested predictive capabilities of the models by comparing flame spectra to model spectra. Measurements were obtained using a single-mode laser (0.004 cm-1 bandwidth) and a widely tunable multi-mode laser operating near 226 nm. We found that a two-level, moving-absorber model of Abrams et al. [Optical Phase Conjugation, (R. A. Fisher, Ed.), p. 234, Academic Press, 1983] gave an excellent description of DFWM line shapes of NO broadened by He, over a range of pressures spanning the Doppler and collisional broadening regimes. We also investigated the dependence of peak DFWM intensities on foreign-gas pressure, confirming a theoretically predicted rapid decrease in DFWM signal intensities with increasing foreign-gas pressure. However, observed intensities decreased more slowly than predicted. In addition, we observed a greatly reduced pressure dependence when the DFWM signals were strongly saturated. DFWM spectra from thermally generated NO in an H2/O2/N2 diffusion flame were obtained with high signal-to-noise ratio and with relatively low saturation. A comparison of a flame spectrum with a model simulation exhibited excellent agreement. The model used the moving-absorber line-shape model and NO spectral data from the literature, and had no adjusted parameters.
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U2 - 10.1016/S0082-0784(06)80193-1
DO - 10.1016/S0082-0784(06)80193-1
M3 - Article
AN - SCOPUS:0027029765
VL - 24
SP - 1653
EP - 1659
JO - Proceedings of the Combustion Institute
JF - Proceedings of the Combustion Institute
SN - 1540-7489
IS - 1
ER -