Abstract
The effects of pressure on outwardly propagating turbulent flames were studied for methane-air mixtures at the equivalence ratios from 0.8 to 1.3 and the initial pressures from 0.10 to 0.50MPa. Turbulence intensity, u' was set to 0.80 and 1.59m/s. The ratios of the turbulent burning velocities to unstretched laminar ones, u_<tn>/u_l increased as the mixture pressure increased. u_<tn>/u_l was affected by the increases in both the turbulence Reynolds number, Re and relative turbulence intensity, u'/u_l due to the mixture pressure increase. And u_<tn>/u_l increased with the decrease in the Markstein number if u'/u_l or the turbulence Reynolds number was constant. The quenching of flame kernel by the turbulence occurred for rich mixture although it did not occur for lean and stoichiometric mixtures at the same Karlovitz number, Ka. It was found to occur when the Markstein Number, Ma was large.
