1. Visualization of the contact line during the water exit of flat plates
- Author
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B. Forest, Sebastien Chalony, Alan Tassin, Jeremy Ohana, T. Breton, Aurelien Tancray, and D. Le Roux
- Subjects
Fluid Flow and Transfer Processes ,Surface (mathematics) ,Physics ,business.industry ,Computational Mechanics ,Time evolution ,General Physics and Astronomy ,Edge (geometry) ,01 natural sciences ,Convexity ,Square (algebra) ,010305 fluids & plasmas ,Acceleration ,Optics ,Mechanics of Materials ,0103 physical sciences ,Diffuse reflection ,Wetting ,010306 general physics ,business - Abstract
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/ $$\mathrm{s}^2$$ . 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).
- Published
- 2017