Golovastov

pp. 130-144

Propagation of the detonation wave in gas mixtures of methane with oxygen in a channel of variable cross section was studied experimentally. Detonation initiation was carried out by spark gap. Deflagration-to-detonation transition was occurred. A composition of the mixtures was selected in such a way that the detonation cell width was several times smaller than the diameter of the channel. The waves velocities and peak pressures at the front of the detonation wave were measured depending on the mixture composition, including a presence of nitrogen. The sizes of the detonation cells were measured using smoked foil mounted inside the channel. The effect of the interference of the shock waves in a conical section was studied. Diagrams of the shock waves, flame fronts, and detonation waves in the combustion chamber depending on the mixture composition are presented.

Influence of methane on diffusion auto-ignition of hydrogen during pulsed discharge escape to the air from a high-pressure chamber was experimentally determined. Pulsed discharge occurred from a high-pressure chamber due to a breakup of the diaphragm. Hydrogen was mixed with air at the contact border. In this case hydrogen ignition point was achieved by means of air heating with a created shock wave which occurred as a result of non-stationary hydrogen discharge from a high-pressure chamber. It was shown that increase in the amount of methane led to increase in the delay of ignition. It was proposed that there is a kinetic mechanism of inhibition of burning in addition to a thermal process. The obtained results could be used for preventing hydrogen ignition in storage and while operating in high-pressure systems.