Enhancement of combustion of a hydrogen-air mixture by excitation of O2 molecules to the a1Δg state

The possibility of increasing the laminar flame velocity in a hydrogen-air mixture by excitation of O-2 molecules into the a(1)Delta(g) singlet state. The presence of 10% of O-2(a(1)Delta(g)) molecules in oxygen is demonstrated to result in noticeable (tip to 50%) enhancement of mixture burning. The temperature of combustion products and also the concentrations of H2O, NO, and other constituents increase. The greatest effect of O-2(a(1)Delta(g)) molecules is manifested in combustion of lean mixtures; the least pronounced effect is observed in rich mixtures. These effects are caused by intensification of the chain mechanism in the presence of a super-equilibrium amount of excited O-2(a(1)Delta g) molecules in a hydrogen-air mixture.