Abstract
Lack of proven means to control ignition impedes practical implementation of homogenous charge compression ignition (HCCI) engines. In the present paper, we investigate if laser-induced excitation of oxygen might aid solution of the ignition control problem in HCCI engines. Simulations by previous researchers showed laser-induced excitation of oxygen enhances ignition in supersonic combustion. Based on this previous research, we extend a chemical kinetic mechanism for propane autoignition to include reactions for two excited oxygen states, O
2
(a
1
Δ
g
) and O
2
(b
1
Σ
g
+
). Simulations examined the effect of each of these excited O
2
states upon ignition timing in an HCCI engine. Results indicate that achieving useful control of the combustion process requires substantial conversion of O
2
to either of the excited states. At the required level of excitation, the power required for the laser may lower engine efficiency.