Laser-initiated ignition of hydrogen-air mixtures

Abstract

The subject of investigation is the kinetic mechanisms intensifying chain reactions that proceed in a hydrogen-air mixture when O2 molecules dissociate under the action of laser radiation with wavelength λ I = 193.3 nm and are excited into the b 1Σ g + electron state by radiation with λ I = 762.346 nm. The efficiencies of both methods to initiate ignition are compared. Numerical simulation shows that the ignition temperature for the laser-induced excitation of O2 molecules into theb 1Σ g + state is lower than for the dissociation of O2 molecules by UV laser radiation, with the energy supplied to the mixture being the same. However, both photochemical methods are much more efficient than mere heating of the mixture by laser radiation or another source of heat.