Investigation of Detonation Behavior of the PBXN 111 Insensitive Charge, by Changing the Dimensions and Position of the Booster Pellet

In addition to the inherent characteristics of explosives, the power of the detonation is affected by arrangement of the explosive train. Therefore, the correct design of the explosive train, especially for insensitive explosive charges containing aluminum, play a fundamental role in order to be more effective. In the current research work, by changing the dimensions of the booster pellet and its position relative to the main charge; the detonation behavior of the main charge has been investigated. In this study, the booster pellet (COMP-A3) is modeled with JWL equation of state and the main charge (PBXN-111) is modeled with ignition and growth equation of state. The simulations has been done using AUTODYN software. The coefficient used in the equation of state (ignition and growth) has been evaluated with experimental results. The simulation results show that by reducing the diameter of the booster pellet from 5cm to 3cm, for a certain length of the booster pellet, reaching to the steady detonation increases due to the greater divergence of pressure wave into the charge. In the case where the booster is inside the charge, the peak pressure values increase in the corners of the charge and adjust the pressure drop due to the divergence. The simulation shows that for the case where the booster and the main charge are placed on top of each other, the booster with a diameter of two centimeters with any length of the booster pellet is not able to create stable detonation in the main charge. For a submerged condition of the same diameter, the booster can produce stable detonation in the main charge. This study showed that a booster pellet with a diameter of 5 cm and a length of 4 cm can cause a complete detonation in PBXN-111. The length of the region to reach stable detonation with this booster is 15 cm.