Research on Parameters Determination of JWL EOS for Commercial Explosives Based on Underwater Explosion Test

In order to conveniently and reliably determine the JWL equation of state (JWL EOS) for detonation products of commercial explosives, an underwater explosion measurement system with a self-developed continuous pressure-conducted velocity probe was designed for measuring the oblique shock wave induced by underwater explosion of cylindrical charge. This system was used to obtain the time history curves of detonation-shock wave front in 3 groups of underwater explosion tests of modified ammonium nitrate / fuel oil (ANFO) charge. The wave fronts were plotted, and other parameters, such as detonation pressure, adiabatic exponent, and included angle of water-gas interface, were calculated by analyzing the underwater explosion of cylindrical charge in two-dimensional steady flow field. Two-dimensional axial-symmetric model of cylindrical charge is built using Autodyn program, and the numerically simulated results of oblique shock wave front and included angle of water-gas interface are compared with the experimental results. The parameters for JWL EOS of modified ANFO are determined by test-and-error method. The simulated results are in agreement with the experimental results. The results show that the error of oblique shock wave front is less than ±5%, and the error of included angle of water-gas interface is less than ±3%. The proposed method is reasonable and reliable for determining the parameters of JWL EOS of large scale commericial explosive. © 2020, Editorial Board of Acta Armamentarii. All right reserved.