Water Impact of a Filled Tank

As statistics show, the water impact of a helicopter in emergency is likely to have tragic consequences. In that, the behaviour of the subfloor is fundamental for accident survivability - especially when in the subfloor structure is integrated a tank. In this work, the impact with the ground and with the water of a filled tank integrated in the helicopter subfloor has been numerically studied. Initially, the numerical model has been developed and validated referring to the experimental data collected during a ground impact of the filled tank. Hence, the impact with the water in the same condition has been investigated. Two different approaches have been adopted to model the fluid: the Lagrangian Finite Element and the Arbitrary Lagrangian Eulerian approaches. Advantages and disadvantages of these approaches have been highlighted and the results show that the Arbitrary Lagrangian Eulerian approach gives an effective advantage in describing the events considered. Finally, on the base of the obtained results, the differences between ground and water impact have been discussed.