Possibility of Initiation of Combustion of CH4–O2(Air) Mixtures with Laser-Induced Excitation of O2Molecules

Abstract

The possibility of initiation of combustion of CH4–O2 mixtures with excitation of O2 molecules to the states a1Δg and b1Σ+ g by laser radiation with wavelengths of 1.268 μm and 762 nm is considered. It is shown that excitation of O2 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 (≈ 0.1 eV per molecule), the ignition temperature of the CH4–O2 mixture with a ratio of 1:2 can be reduced from 1000 to 300 K.