Experimental investigation of influence of methane additions on spontaneous self-ignition of pulsed jet of hydrogen

• Spontaneous self-ignition of hydrogen–methane impulse jet was investigated.
• Ignition delays were measured in dependence on methane addition and initial pressure.
• Thermodynamic analysis of the effect of impurities was carried out.

The influence of addition of methane on the self-ignition of a hydrogen jet was studied experimentally for the pulse discharge into an open channel filled with air. During the pulse discharge from a high pressure chamber a shock wave is formed, which heats the surrounding air and a contact surface. The self-ignition of the jet occurred at the contact surface of the jet with air. A mixture of hydrogen with methane was preliminary prepared in a vessel of 40 L. The initial pressure of the mixture was varied from 3 to 15 MPa. During the discharge of the binary mixture ignition delays were measured relative to the moment of a breaking of the diaphragm. Ignition delays were determined by a photomultiplier tube. The delays were measured for different initial pressures and the methane addition. A molar concentration of the methane addition varied from 5% to 18%. Analysis of the effect of impurities on the thermodynamic parameters of the pulsed jets was carried out.