Steady Detonation Waves in Right Circular Cylinders of Non-ideal Explosives

Abstract

This chapter overviews the detonation properties in right circular cylinders of non-ideal HE's. This requires some understanding of 2-D hydrodynamic flow and modified ZND theory for non-ideal HE's. This chapter will first cover the modified ZND detonation theory for non-ideal HE's. Then a review of experimental techniques using right circular cylindrical samples will be presented since detonation science's understanding is primarily based on the large experimental data base from cylindrical samples. This will be followed by curved detonation front theory for right circular cylindrical samples and a brief overview of select 2-D flow conditions.Most explosive detonation wave properties are obtained from finite size right circular cylindrical HE samples so it is important to understand how this cylinder geometry effects detonation properties for HE's. Two important features are curved wave fronts and size dependence of properties. Detonation velocities are a functions of diameter (velocity decrement data), initial density, and confinement. Ideal explosives exhibit slight detonation velocity size dependence only near its failure diameter and then fail to propagate a steady detonation wave for smaller diameters. Non-ideal explosives have large variation of detonation velocities as a function of size compared to ideal explosives. Experimental data presented on non-ideal PBXN-111 will demonstrate this feature.The CJ detonation model does not treat the detonation velocity dependencies as a function of charge size. A modified ZND model can explain some of the detonation velocities properties and allows the determination of the sonic reaction zone length. Neither detonation model directly treats the strong dependency of detonation wave velocity on initial density. Non-ideal ExplosivesThe simplest definition of a non-ideal HE is that energy release continues beyond the sonic plane of a steady detonation front [1,2]. Recall the sonic point behind the steady detonation front is where D ¼ u products + c products . Energy release J.W. Forbes, Shock Wave Compression of Condensed Matter, Shock Wave and High Pressure Phenomena,