On combustion enhancement mechanisms in the case of electrical-discharge-excited oxygen molecules

Combustion intensification mechanisms in a supersonic flow of a hydrogen-oxygen mixture behind the oblique shock wave front are investigated for the case when vibrations and the a 1Δg and b 1Σ g + electron states of a O2 molecule are excited by an electrical discharge. The presence of vibrationally excited and electronically excited O2 molecules in the oxygen plasma allows intensification of the chain mechanism in the H2-O2 mixture even if the energy put into O2 molecules in the discharge is low. Excitation of O2 molecules is several tens of times more efficient for acceleration of oxygen-hydrogen mixture combustion than mere heating of the gas by an electrical discharge. In addition, low-temperature inflammation of the mixture with electrical-discharge-excited O2 molecules makes it possible to raise the efficiency of conversion of the reactant chemical energy to heat compared with the conventional way of combustion initiation by heating.