Model of non-ideal detonation of condensed high explosives

Abstract

The Zeldovich-Neumann-Doering theory of ideal detonation allows one to describe adequately the detonation of charges with near-critical diameter. For smaller diameters, detonation velocity can differ significantly from an ideal value expected based on equilibrium chemical thermodynamics. This difference is quite evident when using non-ideal explosives; in certain cases, this value can be up to one third of ideal detonation velocity. Numerical simulation of these systems is a very labor-consuming process because one needs to compute the states inside the chemical reaction zone, as well as to obtain data on the equation of state of high-explosive detonation products mixture and on the velocity of chemical reaction; however, these characteristics are poorly studied today. For practical purposes, one can use the detonation shock dynamics model based on interrelation between local velocity of the front and its local curvature. This interrelation depends on both the equation of state of explosion products, and the reaction velocity; but the explicit definition of these characteristics is not needed. In this paper, experimental results are analyzed. They demonstrate interrelation between the local curvature of detonation front and the detonation velocity. Equation of detonation front shape is found. This equation allows us to predict detonation velocity and shape of detonation wave front in arbitrary geometry by integrating ordinary differential equation for the front shape with a boundary condition at the charge edge. The results confirm that the model of detonation shock dynamics can be used to describe detonation processes in non-ideal explosives.