Deflagration-to-detonation transition in stochiometric mixtures of the binary methane–hydrogen fuel with air

Abstract The previously proposed experimental method for evaluating the detonability of fuel–air mixtures, based on measuring the run-up distance and/or run-up time of deflagration-to-detonation transition (DDT) in a standard pulsed detonation tube, was applied to study the DDT in the stoichiometric air mixtures of the binary methane–hydrogen fuel with a volume fraction of hydrogen ranging from 0 to 1 under the fixed thermodynamic and gasdynamic conditions. Based on the known data on combustion and self-ignition of such a fuel, it was expected that the DDT run-up distance and time should gradually decrease with hydrogen concentration. Contrary to expectations, the dependences of DDT run-up distance and time on the volume fraction of hydrogen turned out to be nonmonotonic: instead of a monotonic decrease, they reach local maxima.