Duran R., Goodrich M., Thomas J., 2012, Propagation of a Vapor Cloud Detonation from a Congested into an Uncongested Area, Chemical Engineering Transactions, 26, 7-12.
A test was conducted which demonstrates that a detonation wave, once formed due to a DDT within a congested region, will propagate as a detonation from the congested region into an uncongested region. This is the expected behavior based on the general behavior of detonation waves and as well as other tests reported in literature. The test rig was 16.5 m (54 feet) long with the first 9.1 m (30 feet) of the rig length comprised of a congested section 3.7 m (12 feet) in width and 1.8 m (6 feet) high. The congestion was made up of a regular array of vertical circular tubes (6 cm (2.375-inch) diameter, pitch-to-diameter ratio of 4.1, area and volume blockage ratios of 23 % and 4.2 %, respectively). The last 7.3 m (24 feet) of the test rig length was completely uncongested. The test rig was configured without any confinement (i.e., no wall or roof sections). A near-stoichiometric ethylene-air mixture completely filled both the congested and uncongested portions of the test rig. Prior testing with a similar rig configuration had shown that this flammable mixture would undergo a DDT within the congested portion of the rig.
