Vented gaseous deflagrations modelling of hinged inertial vent covers

The model of explosion pressure build up in enclosures with inertial vent covers and the CINDY code implementing the model are validated against experiments by Hochst and Leuckel (1998) in a 50 m3 vessel with a pair of ceiling-mounted upwards-opening hinged doors in a 'butterfly' configuration with surface densities of 73 and 124 kg/m2 under conditions of initially quiescent and turbulent mixtures. The model and the code are further validated against an experiment by Zalosh (1978) in a 33.5 m3 room-like enclosure with a pair of wall-mounted rectangular doors, in a parallel configuration, each hinged at its bottom edge with a surface density of 23.1 kg/m2 and initially quiescent mixture. A formula for the torque acting upon a rotating venting door is derived under conditions of vent cover jet formation. The vent cover jet effect decreases the torque three times compared to an elementary approach valid at the start of vent cover movement. It is demonstrated that, similar to translating vent covers, the vent cover jet effect is crucial for prediction of interdependent vent cover displacement in time and pressure transients.