Mitigation of shock waves within a liquid filled tank

An experimental study was implemented in order to understand the pressure generated by a hydrodynamic ram event. This event was created by firing spherical projectiles into a large 1000 gallon water tank that was used to simulate an aircraft fuel tank. Standard high-speed video and a large-scale shadowgraph technique were used to visualize pressure waves produced from the projectile impact and to relate the images to pressure transducer measurements. Four different geometries of triangular bars were installed within the simulator to provide shock wave mitigation of the internal pressures. Pressure transducers recorded the initial pressure wave and the cavity collapsing pressure and related these to the back wall pressure. These pressure differences were compared to those generated by projectiles in the absence of the shock mitigating members and it was determined that the hydrodynamic ram effect can be reduced with the appropriate design of such an assembly.