A Simplified Model for Explosion Venting Due to the Separation of a Heavy Protective Cover

Abstract

The paper presents a study aiming at simulation and understanding of some characteristics of an interior explosion within a room with an opening, that is initially being closed by a heavy cover, and may open gradually due to the effect of the explosion products. An effective simplified model of explosion venting due to separation of the protective cover has been developed. The developed model with lumped parameters is based on the Bernoulli equation and describes the quasi-stationary phase of the vented interior explosion. The initial internal gas pressure induced by the very short non-stationary phase is predicted by the developed approximate analytical formula, based on the full energy conservation law. The formula yields very good agreement with experimental data and with numerical analysis results. The simulation of the unsteady outflow from a cylindrical high-pressure vessel upon a sudden separation of the cover has shown that the developed simplified model yields the integral characteristics of the outflow process (such as a maximum cover's velocity and displacement etc) with reasonable accuracy. The proposed approach is demonstrated by the simulation of gas outflow from a chamber upon a sudden separation of the cover or upon a rectangular shutter rotation about a fixed line hinge. The analysis has been performed using the developed simplified approach and through simulations with AUTODYN. A good correspondence between both methods has been obtained. The effect of gravity on the protective cover velocity and displacement has been also examined.