Visualization of the contact line during the water exit of flat plates
|Author(s)||Tassin Alan1, Breton Thibaut1, 2, Forest Bertrand1, Ohana Jeremy1, Chalony Sebastien1, Le Roux Dominique1, Tancray Aurelien1|
|Affiliation(s)||1 : IFREMER, ZI Pointe Diable, CS 10070, F-29280 Plouzane, France.
2 : ENSTA Bretagne, FRE CNRS 3744, IRDL, F-29806 Brest 09, France.
|Source||Experiments In Fluids (0723-4864) (Springer), 2017-08 , Vol. 58 , N. 8 , P. 104 (1-9)|
|WOS© Times Cited||7|
We investigate experimentally the time evolution of the wetted surface during the lifting of a body initially floating at the water surface. This phenomenon is referred to as the water exit problem. The water exit experiments were conducted with transparent (PMMA) mock-ups of two different shapes: a circular disc and a square flat plate. Two different lighting systems were used to diffuse light in the mock-up material: a central high-power LED light normal to the surface and an edge-lighting system featuring an array of LED lights. These setups make it possible to illuminate the contact line, which delimits the surface of contact between the mock-up and the water. The characteristic size of the mock-ups is about 20 cm and the acceleration of the mock-up oscillates between 0 and 25 m/s2. We show that the central light setup gives satisfactory results for the circular disc and that the edge lighting technique makes it possible to follow a contact line with a time-evolving complex shape (strong changes of convexity) up to 1000 fps. The observations presented in the paper support the possibility of extending this promising technique to more general three-dimensional bodies with arbitrary motion (e.g., including pitch motion).