On the influence of electronically excited oxygen molecules on combustion of hydrogen–oxygen mixture

This communication reports on the experimental observation of the shortening of the induction zone length in a premixed mode of combustion in a subsonic H2–O2 low pressure flow due to the presence of oxygen molecules excited to the singlet a 1Δg electronic state. The low pressure electric glow discharge was used to produce singlet oxygen molecules. The analysis showed that even a small number of O2(a 1Δg) molecules (~1%) in the H2–O2 mixture allows one to noticeably reduce the ignition delay length and to ignite the mixture at a lower temperature. The results obtained exhibit the possibility to intensify the combustion of a hydrogen–oxygen mixture by means of excitation of O2 molecules by electrical discharge at low pressure (P = 10–20 Torr).