Limits and mechanism of detonation re-initiation behind a multi-orifice plate

An experimental investigation was performed to establish the dependence of concentration limits of detonation re-initiation behind a multi-orifice plate on mixture composition and initial pressure for hydrogen–air mixtures. The experiments were carried out in detonation tubes of diameter 106 and 141 mm, separated by a multi-orifice plate into two sections. The tubes were equipped with pressure gauges and a semi-cylindrical smoked plate. It is shown that initial pressure has strong influence on the value of concentration limit, especially for lean hydrogen–air mixtures. On the basis of soot records it can be inferred that re-initiation occurs due to two different mechanisms that depend on the mixture sensitivity and properties of the multi-orifice plate.