Phase velocity enhancement of linear explosive shock tubes

Abstract

Strong, high-density shocks in a gas can be generated by end-initiating a hollow cylinder of explosive surrounding a pressurized thin-walled tube. Implosion of the tube results in a pinch that travels at the detonation velocity of the explosive, thereby driving a strong shock into the gas ahead of it. In the present study, the pinch velocity was increased beyond the detonation velocity of known explosives by dragging an oblique detonation wave along the surface of the tube. The gas shock and detonation trajectories were measured for a variety of phase velocities and tube fill pressures. Strong shocks with an average velocity of 13 km/s were observed for fill pressures as high as 6.9 MPa in helium while transient velocities as high as 19 km/s were observed. Shock trajectory performance degraded strongly with increasing phase velocity and for a velocity of 16 km/s the gas shock barely advanced ahead of the detonation. © 2012 American Institute of Physics.