Possibility of initiation of combustion of CH4-O2 (air) mixtures with laser-induced excitation of O2 molecules

The possibility of initiation of combustion of CH4-O-2 mixtures with excitation of O-2 molecules to the states a(1)Delta(g) and b(1)Sigma(g)(+) by laser radiation with wavelengths of 1.268 mum and 762 nm is considered. It is shown that excitation of O-2 molecules significantly decreases the induction period and ignition temperature because of accelerated formation of active atoms and radicals and intensification of the chain mechanism of the process. Even if the specific energy of laser radiation absorbed by the gas is low (approximate to0.1 eV per molecule), the ignition temperature of the CH4-O-2 mixture with a ratio of 1: 2 can be reduced from 1000 to 300 K.