Modelling of PBX-115 Using Kinetic CHEETAH and the DYNA Codes
Abstract
PBXW-115, a highly non-ideal explosive tailored for underwater effects and composed of 43% ammonium perchlorate, 25% aluminium, 20% RDX and 12% HTPB binder, has been studied using Kinetic CHEETAH (the Lawrence Livermore National Laboratory CHEETAH 2.0 code), the three-term "Ignition and Growth" Model incorporated into the explicit finite element hydrocode LSTC-DYNA, and the CPeX Reactive Model based on the small divergent detonation theory of Wood and Kirkwood in DYNA2D. This report firstly focuses on a series of simulations performed using Kinetic CHEETAH based on the Wood-Kirkwood detonation theory using a pressure exponent of 2 in the pressure-dependent rate law. It was found that CHEETAH could predict the trend of the detonation velocity as a function of charge diameter, but overestimated the detonation velocities. The agreement was improved with further parameter adjustment, by decreasing the pressure exponent in the rate law from 2.0 to 1.0, and then 0.5. The reaction zone widths over a wide range of charge radius were also computed. Attention was then turned to hydrocode modelling, with particular interest in developing reactive models for PBXN-111 and PBXW-115 (Aust). Both the "Ignition and Growth" Model and the CPeX Model were calibrated against the experimentally observed dependence of detonation velocity on charge diameter in unconfined charges of both PBXW-115 (Aust) and US PBXN-111. These two reactive models were validated by comparing their predictions against experimental data for detonation of charges confined in 2.5 mm and 3 mm thick brass. The Ignition and Growth Model was then applied successfully to the simulation of aquarium tests. Finally, to test whether the two models using parameters derived from small-scale tests can be applied to large-scale devices, these two models were applied to the simulation of mid-scale underwater tests of PBXW-115 (Aust), and comparisons with available data are made.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2003
- Accession Number
- ADA421656
Entities
People
- David L. Kennedy
- Jing P. Lu
Organizations
- Defence Science and Technology Group