Experimental investigation on detonation initiation with a transversal flame jet

This paper reports on an investigation of detonation initiation with a transversal flame jet. Series of single-cycle experiments are performed, where stoichiometric propane–oxygen mixtures with nitrogen dilution at atmospheric initial pressure are used, both in the flame sub-chamber with varying configurations and in the test tube 70 mm in diameter and 1550 mm long. The experimental results show that the flame jet orifice diameter slightly affects the detonation initiation sensitivity, and the flame sub-chamber configurations exert a minor effect on the deflagration-to-detonation transition (DDT) distance, but the DDT time decreases as the flame sub-chamber length increases. Conventional spark ignition is investigated as a comparison experiment, and detonation initiation is not observed in mixtures with nitrogen dilution up to 65%.