Confined Kerosene Vapor Explosion: Severity Prediction Laws Based on Numerical Simulations.

Abstract

The vulnerability of aircraft, if attacked by conventional weapons, depends notably on the possibility to initiate and to propagate a combustion reaction in the multicompartmented kerosene tanks. After a review of the related mechanisms and existing studies, the numerical simulation tool MIRAGE (french acronym for gas flow adaptable and transient reactive modeling) is used extensively to investigate the effects of four parameters: the ignition energy (from 5 to 1000 J), the equivalence ratio in air (from 0.3 to 2.19), the tank pressure (from 1 to 1.8 bar absolute), and its volume (from 0.4 to 2 m 3 ). A detailed kinetic mechanism is considered (207 species, 1592 reactions) to properly represent the chemistry. The maximum pressure after explosion is found to depend mainly on the initial pressure and on the equivalence ratio, but not on the tank volume or the applied energy. A critical value of the energy, corresponding to the limit between ignition and no ignition, is shown depending on the equivalence ratio but also on the initial pressure of the tank. Thanks to these results of "numerical experiments", empirical laws are proposed to estimate the overpressure and its dynamic depending on the preceding four parameters. These laws are also applied to some test cases of the literature, with good agreement.

Simulation of the explosion of kerosene vapors inside a partitioned structure

“…The physical processes involved in ignition and combustion of fuels like kerosene are generally complex. Classical models take into account thermal and radiative transfers, the heat of combustion and a complete development of the chemical kinetics with numerous reactions [5]. The corresponding calculation codes are generally heavy and their predictions often remain limited for partitioned vessels.…”