The hydrodynamic RAM effect: Review of historic experiments, model developments and simulation

The Hydrodynamic Ram (HRAM) effect occurs when a high kinetic energy projectile penetrates a fluid filled area, e.g., a liquid filled tank. The projectile transfers its momentum and kinetic energy to the fluid, what causes a sudden, local pressure rise, further expanding as primary shock wave in the fluid and developing a cavity. It is possible that the entire tank ruptures due to the loads transferred through the fluid to its surrounding structure. In the past decades, additionally to experimental investigations, HRAM has been studied using various computational approaches particularly focusing on the description of the Fluid-Structure Interaction (FSI). This article reviews the published experimental, analytical and numerical results and delivers a chronological overview since the end of World War II. Furthermore, HRAM mitigation measures are highlighted, which have been developed with the experimental, analytical and numerical toolboxes matured over the past 80 years.