Specific features of the mechanism of flame propagation in rich hydrogen–propane–air mixtures

Propagation of a planar laminar flame in rich homogeneous propane–air and hydrogen–propane–air mixtures is numerically studied. It is shown that the maximum burning temperature is higher than the thermodynamically equilibrium value and is reached when chemical and physical processes have not been yet completed. The degree of superadiabaticity depends on the ratio of hydrogen and propane concentrations. Superadiabaticity in rich hydrogen–propane–air mixtures, in addition to the inhibiting action of propane, determines the deviation from Le Chatelier's principle for flammability limits in these mixtures.