Gurney Velocity Relationships

Abstract

Gurney theory calculates the explosive energy imparted to metal casings during detonation and fragmentation. This paper assesses relationships between Gurney theories and Hydrodynamic Work energy. Several relations found theoretically are compared with trials data. Aluminised explosives are included as part of this data set. This paper builds on the author’s work in establishing theoretical relationships between Gurney velocity, Gurney energy and Hydrodynamic Work energy for Gurney theories. An improved generalisation of both Cooper’s and Koch’s Gurney theories is derived, which is simple to apply and gives improved predictions. This transforms Cooper’s and Koch’s simpler theories into the more accurate Kamlet and Finger Gurney theory, by use of an explosive coefficient (fX), which is a function of the unreacted explosive density. The ratio of Gurney energy to Hydrodynamic Work energy using this methodology is shown as identical to that previously determined for Kamlet & Finger’s Gurney theory and typically is 62%.