A Shock Tube Study of the Reaction CH+NO⇋Products Using a Perturbation Method

  • Michael W. Markus
  • Paul Roth
Conference paper


A ring dye laser spectrometer was employed for in-situ measurements of CH concentrations in the reaction zone behind reflected shock waves. The time dependent absorption in the Q-branch of the A 2Δ - X 2Π band of CH at 431.1311 nm caused by the formation and consumption of CH radicals during the shock induced pyrolysis of a few ppm ethane in argon was recorded. The CH concentration could directly be calculated from the measured absorption by using spectroscopic data. The addition of some amount of NO to the initial hydrocarbon/argon mixtures leads to a significant reduction of the CH concentration during the reaction time mostly due to the direct reaction of CH radicals with the added molecules. The perturbed and unperturbed profiles were compared with those calculated by computer simulations based on a kinetic model. By a fitting procedure a rate coefficient for the most important perturbation reaction:
$$CH + NOproducts,{k_1} = 8.10 \times {10^{13}}c{m^3}mo{l^{ - 1}}{s^{ - 1}}$$
could be determined. The given value which is valid in the temperature range between 2500 K and 3700 K at pressures about 1 bar confirms the few high temperature data available in literature.

Key words

Hydrocarbon Nitrogen oxyde Reaction products 


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Copyright information

© Springer-Verlag Berlin Heidelberg 1995

Authors and Affiliations

  • Michael W. Markus
    • 1
  • Paul Roth
    • 1
  1. 1.Institut für Verbrennung und GasdynamikUniversität DuisburgDuisburgGermany

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