Experiments on the water entry and/or exit of a cone

International audienceWe report on recent experiments of water exit and combined water entry and exit. The water exit phenomenon refers to the lifting of a body initially floating at the water surface (pure exit) or to the lifting of a body just after a water entry phase (combined water entry and exit). Water exit is relevant to different fields of applications (e.g. marine and naval engineering, aeronautics, biomechanics) and is known for generating suction loads on structures. This work is the continuation of the first experiments presented in Tassin et al. (2017a) and Tassin et al. (2017b) dedicated to the water exit of flat plates. The experimental approach investigated previously is now extended to three-dimensional bodies such as a cone with a deadrise angle of 15 ◦ and to mock-ups of bigger scale (up to 50 cm diameter). In particular, the LED edge-lighting previously used to illuminate the contact line during the water exit of a transparent modified square plate has been adapted to the tracking of the contact line during the water exit of a transparent conical shell. New water exit experiments were also carried out with a circular disc of 40 cm diameter in order to study the influence of the body shape. We also performed combined water entry and exit experiments with a conical mock-up in order to investigate the performance of the LED edge-lighting technique for the tracking of the contact line during the entry stage. Following our previous work (see Tassin et al. (2017a)), the accuracy of the LED edge-lighting technique during cone water exit was assessed through comparison with experiments during which a draughtboard was placed at the bottom of the tank