Numerical simulation of the deflagration to detonation transition behavior in explosives based on the material point method

The problem of the deflagration to detonation transition (DDT) in explosives has been concerned seriously for many years, but the existing numerical models have different defects. It is difficult for them to accurately and quantitatively describe the DDT process of explosives under complex conditions (such as different constraint conditions). On the basis of the material point method, the DDT numerical model of explosives under complex conditions is established by using the heat balance equation, EOS of JWL, EOS of Virial and Lee-Tarver equation in this paper. In the model, the combustion reaction and detonation reaction of explosives can be described, and the influence of constraint condition on the DDT process of explosives is considered. Meanwhile, DDT critical condition of explosives and the judgment method of the starting position of explosive detonation reaction are given. The model is used to simulate the DDT process of COM B explosive constrained by steel tube in this paper. The simulation results show that the stable detonation velocity is about 7700 m/s, the stable detonation pressure is about 0.325 Mbar, and the induced detonation distance is 30.2 cm. Analysis found that the detonation reaction of COM B explosive occurred in the incomplete combustion area. The simulation results are in agreement with the experimental results in literature, which verifies the correctness of the model proposed by this paper. (c) 2021 The Combustion Institute. Published by Elsevier Inc. All rights reserved.