Abstract Previously published simplified n-alkane cool-flame chemistry is re-evaluated for n-dodecane. Comparison with experimental results produces improved rate-parameter estimates for n-dodecane and indicates deterioration of the simplified chemistry with increasing pressure in predictions of droplet diameters at cool-flame extinction.
Abstract The Rayleigh index of counterflow hydrogen–air diffusion flames is employed as a vehicle for quantifying inaccuracies of predictions caused by the introduction of reduced chemistry to decrease computation times. Inaccuracies of a systematically reduced 2-step mechanism, derived from a detailed 12-step mechanism for hydrogen–air systems, are small at low strain rates but become appreciable as extinction is approached.
Abstract A one-step reduced mechanism for hydrogen combustion, previously developed for fuel-lean flames, is extended to apply for all equivalence ratios under near-limit conditions by taking into consideration two additional recombination steps that are important under fuel-rich conditions. It is found that the crossover temperature that appears in the cutoff factor is smaller under fuel-rich conditions. Besides improving insights, the results can be beneficial in speeding computations.