Numerical Model of Fragmentation Hazards Caused by a Tank Explosion

Abstract

The paper analyses the fragmentation of a horizontal cylindrical tank caused by the effect of boiling liquid expanding vapour explosion (BLEVE). A fragmentation model for identification of kinematic parameters is proposed. The originality of the model lies in the introduction of initial acceleration. Using this model, the initial velocity can be assessed without knowing the values of explosion energy and the mass of fragments. The application of this model reduces the uncertainty in assessing the range of fragments and the risk of fragmentation. The initial acceleration of fragments generated in an explosion is assessed according to the geometry and type of the tank material. The initial acceleration, which does not depend on the kinematic parameters of the constant wall thickness of the tank, allows a reliable assessment of the launch angle of a fragment. Characteristic forms of the fragment trajectory are identified, depending on the aerodynamic and thrust acceleration coefficients, and probability distributions of the fragment ranges are given. Relevant factors in the assessment of fragmentation hazards include the trajectory of a fragment, the height of a target and its distance from the tank. It was concluded that aerodynamic fragments at distances of up to 50 m are not a danger to targets of up to 15 m high. Fragments with high air resistance and low thrust can endanger targets of the same height at distances of over 200 m. The presented fragmentation model includes the effect of heating due to the BLEVE effect and can be applied to all types of tanks.