The Use of the Propellant Specific Impulse for the Prediction of the Prompt and Terminal Gurney Velocity of High Explosives

Simple relationships are presented for the calculation of both prompt and terminal Gurney velocity of chemical high explosives. By considering that a given explosive behaves like a propellant, its specific impulse [GRAPHICS] was calculated using Mader's ISPBKW code; it was found that the density impulse ( [GRAPHICS] where [GRAPHICS] is the explosive density and [GRAPHICS] is an empirically optimized variable) performance factor correlates well with the terminal Gurney velocity of both ideal and nonideal explosives. Furthermore, the cylinder wall energy can be computed from ( [GRAPHICS] from which the prompt Gurney velocity can be obtained through the application of the Gurney's cylinder equation. It was concluded that ( [GRAPHICS] is a powerful factor for the prediction of the Gurney velocities, especially for nonideal compositions.