Impact of inflated structures on a liquid free surface.

S. Halbout (1) , Nicolas Malleron (1, 2) , Fabien Remy (2, 3) , Yves-Marie Scolan (2, 3)

1 Eurocopter France
2 IRPHE - Institut de Recherche sur les Phénomènes Hors Equilibre
3 ECM - École Centrale de Marseille

There are many situations where inflated structures may hit violently a liquid free surface. One of them occurs during sea-landing of helicopters. As a matter of fact helicopters are equipped with inflated floaters. Those floaters are made of impermeable tissues which are almost inextensible and their flexural rigidity is small. These mechanical characteristics are difficult to reproduce at model scales, that is why we found more conventional inflated balloons like space hopper. Experiments have been carried out in the flume of Ecole Centrale Marseille. Only qualitative measurements have been performed. High speed camera provided the main features of the phenomenona. This abtract sums up this experimental campaign and the first attempts done in the numerical modellings thus yielding some comparisons. It is shown that simple linearized models- both structural and hydrodynamic models - can reproduce the early stage of penetration when impact occurs.

Domaines: Mécanique des fluides [physics.class-ph]; Mécanique des fluides [physics.class-ph]

S. Halbout, Nicolas Malleron, Fabien Remy, Yves-Marie Scolan. Impact of inflated structures on a liquid free surface.. 23rd International Workshop on Water Waves and Floating Bodies, Apr 2009, Zelenogorsk, Russia. 4pp. ⟨hal-00458073⟩