Vented gaseous deflagrations: Modelling of spring-loaded inertial vent covers

The model of vented explosion dynamics in an enclosure with inertial vent covers is advanced further by the option of a spring-loaded cover acting as venting device. The model and CINDY code are used to process by the inverse problem method the experiments by Wilson in a 1.7 m3 vessel with spring-loaded valves with surface densities of up to 245 kg/m2 at conditions of initially quiescent and turbulent mixtures. It is demonstrated that, similar to translating and hinged vent covers, modelling of the vent cover jet effect is crucial for reasonable prediction of interdependent explosion pressure-time and cover displacement-time transients. The spring constant k was determined through backfitting, and reflects not only the resistance of the cover springs to the internal vessel pressure, but also the cycling frequency of the cover during deflagration. The turbulence factor was found to rise during venting.