Equivalence ratio dependence of reactivity of low and high temperature reactions for ultra-lean gasoline surrogate/air weak flames in micro flow reactor with controlled temperature profile

A vertical-type micro flow reactor with a controlled temperature profile was used to investigate the effect of the equivalence ratio on low and high temperature reactions of ultra-lean gasoline surrogate/air weak flames. Surrogates of research octane number 90 and 100 were used at equivalence ratios between 0.50 and 1.00. In the experiments, leaner mixtures showed a higher reactivity as indicated by hot flames stabilizing at lower wall temperatures. In 1D steady computations by PREMIX only LLNL mechanism was able to reproduce this trend. This was accounted to difference in the reaction parameters of the chain termination reaction H+O₂(+M)=HO₂(+M) in the KUCRS mechanisms. Once LLNL's parameters were introduced, results by KUCRS and SIP mechanisms were able to reproduce the experimental results with higher accuracy.