Efficient Hydrodynamic Ram Test Chamber

Ballistic impact on an aircraft fuel tank skin generates a pressure pulse in the fuel that can cause catastrophic structural damage by hydrodynamic ram (HRAM). The Air Force RAMGUN facility simulates this impulsive hydrodynamic loading for experimental testing of candidate structural joints. A projectile fired by a gas gun impacts one end of a water-filled chamber, launching a pressure wave that impinges on a test article at the opposite end.Unfortunately, the pressure pulse in the liquid excites a structural wave in the steel chamber that moves faster, arriving at the test section well in advance and perturbing both the test article and the diagnostics.We will design a test chamber that delays the structural wave relative to the pressure pulse, effectively isolating the test article from perturbation and improving experimental results. In addition, our design will improve energy transfer from the projectile to the water, extending the test range of the facility, and will facilitate scaling of the test section to larger diameter for testing full-scale joints.