The passage of explosions through narrow cylindrical channels

Abstract

The transmission of explosions through narrow channels is investigated in this paper. The channelsconnect the explosion chambers. Ignition in the outer chamber following firing of an explosion mixture in the inner chamber of depends on the geometry of the channel. It has been found that a propagating methane air flame does not travel through channels of less than about 3mm diameter, although ignition may still occur in the outer chamber. The hot burns gases from the inner chamber issue into the outer chamber and may level to ignition which originates in the hot eddies ofthe turbulent jet. Ignition or one-ignition depends mainly on the gas dynamic properties of the jet, which in turn depend on the channel geometry. This mode of ignition is confirmed by theoretical considerations, as well as by the nature of the exprimental results showing, for example, that very short channels are more efficient in preventing outside ignition than channels of about 10 mm length. Schlieren pictures of the outside ignition process also confirm the proposed mechanism.