Energy Transfer to a Rigid Piston under Detonation Loading

The flow following the impact of a plane detonation front, in a condensed organic explosive, on a rigid piston is obtained by a finite difference procedure. The equation of state E = Pv/(γ−1) is used for the gaseous explosion products with γ equal to 2.5, 3.0, and 3.5. Explicit formulas for the piston motion are obtained analytically for γ = 3. The effects of the detonation parameters and the explosive-mass to piston-mass ratio on the terminal velocity of the piston and on the energy transmitted to the piston are described. For γ = 2.5 to 3.5, the terminal velocity of the piston depends almost entirely on the chemical energy released in the explosion and on the explosive-mass to piston-mass ratio; i. e., for a fixed chemical energy, the total energy transmitted to the piston is insensitive to the form of the detonation wave.