Ignition of Multicomponent Hydrocarbon/Air Mixtures behind Shock Waves

Experimental and numerical investigations are performed of the temperature dependences of delays in the ignition, behind shock waves, of multicomponent mixtures simulating the products of steam conversion of methane. Experimental investigations are performed in the temperature range from 930 to 1880 K at pressures from 2.5 to 9 atm. It is demonstrated that ignition delays in mixtures of air with products of 50 and 100% steam conversion of methane may be described using the results of numerical calculations based on the known kinetic schemes of methane combustion. At the same time, a considerable (by a factor of two–three) reduction of delays in the ignition of methane/air mixtures during addition of steam is observed and discussed, which is not described by the known kinetic schemes. The obtained results may be used in developing hypersonic scramjet engines.