Small-Scale Experiments using Explosively Compressed Gas to Drive Hypervelocity Projectiles

The ability to drive projectiles to hypervelocities (V≥2.5 km/s) is vital to understand how materials behave in high-speed flight and impact scenarios, such as atmospheric entry and crater formation seen with meteoroids. Although there are several capabilities that can achieve these extreme velocities, such as the powder gun and light-gas gun, these capabilities are rather large and stationary, requiring a dedicated facility for operation. The portable and small-scale device presented in this work is similar to the two-stage light-gas gun in which it utilizes energetic material to compress a light-gas and can drive a projectile to hypervelocities. Instead of utilizing a piston, as seen in the two-stage light-gas gun, the device uses explosives to collapse the walls of a light-gas filled cylinder. As the explosive detonates along the length of the tube, the collapsing wall acts like a piston and will compress the light-gas. In this study, computational modeling was used to evaluate projectile velocities at different initial gas fill pressures. Testing of the small-scale prototype was conducted to validate the velocities from computational modeling. The results of this study demonstrate the velocity range of the test capability.

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