Initiation of combustion and detonation by laser induced electronical excitation of O_2 molecules to the a~1Δ_g and b~1Σ_g~+ states

摘要

On the basis of developed physical and mathematical model for thermal nonequilibrium chemical processes involving electronically excited molecules the analysis of the mechanisms resulting in initiation of combustion in closed reactor and detonation in supersonic flow behind inclined shock wave in H_2+O_2(air) mixtures at excitation of the a~1Δ_g and b~1Σ_g~+ states of oxygen molecules by resonant laser radiation with wavelengths λ=1.268 μm and 762 nm has been carried out. The numerical analysis has shown that induced by laser radiation excitation of O_2 molecules leads to significant decrease of the autoignition temperature and allows to initiate detonation at very low temperature (～500 K) behind shock wave at relatively small values of laser radiation intensity. Excitation of O_2(b~1Σ_g~+) state by laser radiation is more effective to influence on combustion kinetics and initiation of detonation in supersonic flow.