Mechanisms and relationships governing the propagation of pyrolysis and combustion waves along a laser beam

The relationships governing the propagation of pyrolysis and combustion waves along an electric-discharge CO₂-laser beam in propane and propane — air mixtures were investigated. It was shown that, after the preliminary conversion of propane in the pyrolysis waves, the average velocity of the combustion wave along the laser beam increases by a factor of 6 — 7. It was established that the velocity of the combustion wave along the beam is proportional to the chain-branching rate constant and that the wave appears as a result of consecutive ignition of the mixture along the beam (analogous to an electric breakdown wave).