Size Effect and Detonation Front Curvature

Abstract

AbstractA simple theory relates the size effect (decrease of the detonation velocity with decreasing radius) of a cylinder with its average sonic reaction zone length, 〈xe〉, i.e. the distance from first reaction to the sonic plane. The size effect is described by where R0 is the radius, Us and D the detonation velocities at R0 and at infinite size and σ is a function describing the extent of wall motion, which is calibrated using four explosives. In this theory, the cylindrical symmetry imposes a quadratic shape to the detonation front. The lag distance at the edge of the cylinder, L0, is related to the reaction zone length by 〈xe〉 ≈︁ L0. Collected results are presented for 56 measured curvatures on 26 explosives, with reaction zone lengths varying from 0.1 mm to 30 mm.