Kinetic analysis of n-decane-hydrogen blend combustion in premixed and non-premixed supersonic flows

摘要

Numerical analysis of ignition and combustion of an n-decane-hydrogen fuel blend in a premixed supersonic flow and in a model scramjet duct is performed using a reduced reaction mechanism built especially to describe the oxidation of blended n-C10H22-H(2)fuel in air at the temperature T-0 > 900-1000K in the pressure range P-0 = 0.1-13 atm. The developed kinetic mechanism involves the principal reactions responsible for chain mechanism development both for n-decane and for hydrogen oxidation. It has been shown that using blended n-C10H22-H-2 fuel makes it possible to enhance the ignition and combustion both in premixed and in non-premixed supersonic fuel-air flows compared to burning pure hydrogen-air and n-decane-air mixtures. This allows high combustion completeness in the scramjet duct at the distance of similar to 1m even at extremely low air temperature T-0 = 1000K and pressure P-0 = 0.3 atm. This is due to the interaction of kinetics of the formation of highly reactive atoms and radicals, carriers of chain mechanism, in H-2-air and n-C10H22-air mixtures.