Water entry of flexible wedges: Some issues on the FSI phenomena

Deformable bodies entering the water can face unexpected Fluid Structure Interaction (FSI) phenomena introduced by the mutual interaction between the fluid motion and the structural deformations. This brief communication presents some preliminary results on the FSI phenomena involved with the water entry of deformable wedges. Wedges with various deadrise angle and flexibility impact the water at different velocities. Two different kinds of FSI are found: (i) a repetition of impacts and separations in the fluid jet and (ii) a tendency to cavitation in the underwater fluid-structure interface. These experimental findings are important since large deformations are found to introduce clearly visible FSI phenomena commonly neglected or ignored, but crucial to correctly predict the hydrodynamic load.