Predicting Coalescence of Blast Waves From Sequentially Exploding Ammunition Stacks

The current requirement that quantity-distance computations for air blast limitations be based on the total weight of all mass-detonating explosives at a storage site may be too restrictive. Therefore, we developed a computer program called 'BWACO', intended to estimate pertinent aspects of the blast environment associated with sequentially detonating, spatially distributed ammunition stacks. This report explains the assumptions used and documents the evolution of BWACO on the Cray following its initial implementation. Comparison of preliminary results with experimental data obtained by Zaker led to replacement of the standard initially used for the description of blast waves with a new standard based on experimental data . BWACO has been adapted for the personal computer with enhanced graphical representations. Application to a number of problems representative of typical ammunition storage configurations are detailed. The results indicate that regions of significant pressure associated with the coalescence of blast wave from distributed ammunition stacks may be less extensive than corresponding regions associated with regulatory requirements. An advantage associated with the distribution of ammunition into smaller subdivisions was also demonstrated. As currently configured, BWACO provides a means of assessing the blast environment associated with the sequential detonation of an arbitrary arrangement of ammunition stacks. The limitations imposed by the assumptions have not been assessed in realistic configurations.