Simulation of the explosion of kerosene vapors inside a partitioned structure

Abstract

The aim of this work is to propose a simple multi-physics model in order to predict the evolution of the thermodynamic variables during the combustion of kerosene vapors in each compartment of a closed vessel. A special attention is paid to the mechanical effects of combustion, e.g. the pressure evolution. The basic characteristics of the model have been developed as part of a Computational Fluid Dynamics (CFD) approach, in order to represent both the ignition stage and the flame propagation in the reactive mixture. The proposed development is validated in a single compartment vessel by investigations about the equivalence ratio and the reaction dynamics (final pressure, combustion duration, etc.). Moreover, the expected phenomenology is correctly reproduced for tanks composed of several compartments, such as for instance, a faster combustion process in presence of internal orifices. The impact of the ignition on the subsequent evolution of the explosion is also investigated, highlighting a strong influence of the ignition location. The model illustrates that the pressure evolution is the result of complex geometry effects: particularly, for a tank made of identical compartments, the total volume is not sufficient to describe the main trends concerning the mechanical effects of the explosion. The calculations are in agreement with classical results available in the literature for a special kind of kerosene (F.34) studied by the laboratory. Despite the proposed model relies on simple assumptions, it represents a useful tool for further vulnerability or risk assessment studies applied to aircraft kerosene tanks.