Modeling of the explosive phase change during a BLEVE event.

A Boiling Liquid Expanding Vapour Explosion (BLEVE) is a physical explosion caused by the sudden bursting of a vessel containing a superheated liquid. The scientific community describes the BLEVE as a physical explosion and is trying to develop models to predict the strength of the shock waves generated. Taking into account the data provided by the experimental campaign on the BLEVE water, this paper focuses on the causes that may lead to the formation of the second external pressure peak. Many authors assume that this peak is influenced by the liquid/vapour phase transition that occurs in the tank after the sudden pressure drop. Using Scilab, a numerical model is created that can solve Euler's equations for the shock tube problem, simulating only the behavior of the vapour phase. The quality of the model is tested taking into account data obtained experimentally in laboratory-scale tests. Then, based on the EVUT (equal-velocity-unequal-temperature) model proposed in the literature, the boiling phenomenon caused by the sudden pressure drop is analysed. The "relaxation time model" is discussed for modelling the source terms. Using the developed model, the effects of boiling on the density, velocity and internal pressure profiles are investigated. Finally, the model is discussed by comparing it with the experimental data from the E27 test of the water BLEVE campaign