Laminar flame speeds of hydrocarbon + air mixtures with hydrogen addition☆

Using the symmetrical, adiabatic, counterflow arrangement, the laminar flame speeds of methane + air and propane + air mixtures, with and without the addition of stoichiometrically small amounts of hydrogen, have been determined by first measuring the flame speeds with stretch and then linearly extrapolating these values to zero stretch. The results show that the flame speed is substantially increased with hydrogen addition, and that it can be linearly correlated with the flame speed without hydrogen addition and a single parameter indicating the extent of hydrogen addition.