Effect of Multiple Vent Parameters on an External Explosion Induced by an Indoor Premixed Methane-Air Explosion

To reveal the influence of vent parameters on the dynamic mechanism of an external explosion induced by a vented premixed methane-air explosion, the evolution process of an outdoor flow field under different vent opening pressures (p(v)), opening times (4), and scaled vent size (K-v = A(v)/V-2/3) is studied by methods of computational fluid dynamics. With an increase in K-v, the shape of the unburned gas cloud and vented flame gradually changes from a jet shape to a depression toward the vent. The outdoor peak specific turbulent kinetic energy increases by 36.5 and 4 times with an increase in p(v) and t(v), respectively. At t(v) = 0.1 s, the peak specific turbulent kinetic energy reaches 1411 m(2)/s(2) and the turbulence range reaches 3 times the length of the room. With an increase in p(v), t(v), and K-v, the occurrence time interval of the external explosion exhibits a decreasing trend. The external explosion is located at a distance of less than 1.4 times the length of the room. At K-v = 0.05, the external explosion occurs at the furthest location.