Comparison of Keller-Miksis model and finite element bubble dynamics simulations in a confined medium. Application to the Hydrodynamic Ram

Hydrodynamic ram (HRAM) is a phenomenon that occurs when a high-speed/high energy projectile penetrates a liquid-filled container. The container must adapt to allow the variation of volume of the cavity created, that generates a large loading due to the liquid momentum. This complex fluid-structure interaction phenomenon has been identified as one of the major threat to aircraft safety. An approach based on bubble dynamics models has been developed by the authors to take this phenomenon into account when designing fuel tanks. In the present work, the authors compare ALE finite element simulations using EUROPLEXUS to a modification of the Keller-Miksis model to account for the confinement effect of the container. In the studied domain, the agreement on the cases simulated is found quite acceptable: 3% and 1% differences respectively in amplitude and period for the bubble dynamic and less than 1% for the impulse transmitted to the structure.