Initiation of combustion and detonation by laser induced electronical excitation of O2 molecules to the a1Δg and b1Σg+ states

On the basis of developed physical and mathematical model for thermal nonequilibriurn 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 alpha(1)Delta(g) and b(1)Sigma(g) states of oxygen molecules by resonant laser radiation with wavelengths lambda=1.268 mum 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 (similar to500 K) behind shock wave at relatively small values of laser radiation intensity. Excitation of O-2(b(1)Sigma(g)(+)) state by laser radiation is more effective to influence on combustion kinetics and initiation of detonation in supersonic flow.