Flow Reactor Experimental Study of H₂/O₂ and H₂/Air Mixtures Ignition Assisted by the Electrical Discharge

ABSTRACT

The paper presents the results of experimental study of the influence of a glow discharge in oxygen on the ignition of hydrogen/oxygen and hydrogen/air mixtures in the low-pressure flow reactor at temperature range 800–1070 K. The study focuses on obtaining the data on the effect of electronically excited molecules O₂(a¹Δ_g) on the ignition delay in presence of the minor amount of other discharge products. In order to reduce the effect of O atoms and O₃ molecules, the walls of the discharge cell and output duct were coated with mercury oxide. The special attention was paid to the diagnostics of discharge products and the evaluation of the influence of reactor walls on the heterogeneous deactivation of O₂(a¹Δ_g) molecules along the reactor. The spectroscopic technique was used for the measurements of O₂(a¹Δ_g) and O₃ concentrations. It was shown that the induction zone length in H₂-O₂ and H₂-air mixtures could be reduced by 10–50% depending on the initial temperature in the case of glow discharge exposure on the oxygen flow.

KEYWORDS:

• H₂/O₂ and H₂/air mixtures
• flow reactor
• ignition
• electric discharge
• singlet oxygen
• experimental study

Acknowledgments

The authors would like to thank O. M. Stelmakh for the inspiring discussion on the topic and V. Silamikelis for the assistance with the experimental setup.

Additional information

Funding

The work was financially supported by the Russian Foundation for Basic Research projects No.[17-08-01423-a] and No. [18-38-00365].