Fourier transform profilometry for water waves: how to achieve clean water attenuation with diffusive reflection at the water surface?

Autor: Philippe Petitjeans, Vincent Pagneux, B. Cabane, Agnès Maurel, A. Przadka
Rok vydání: 2011
Předmět:
Zdroj: Experiments in Fluids. 52:519-527
ISSN: 1432-1114
0723-4864
DOI: 10.1007/s00348-011-1240-x
Popis: We present a study of the damping of capillary-gravity waves in water containing pigments. The practical interest comes from a recent profilometry technique (FTP for Fourier Transform Profilometry) using fringe projection onto the liquid-free surface. This experimental technique requires diffusive reflection of light on the liquid surface, which is usually achieved by adding white pigments. It is shown that the use of most paint pigments causes a large enhancement of the damping of the waves. Indeed, these paints contain surfactants which are easily adsorbed at the air–water interface. The resulting surface film changes the attenuation properties because of the resonance-type damping between capillary-gravity waves and Marangoni waves. We study the physicochemical properties of coloring pigments, showing that particles of the anatase (TiO2) pigment make the water surface light diffusive while avoiding any surface film effects. The use of the chosen particles allows to perform space-time resolved FTP measurements on capillary-gravity waves, in a liquid with the damping properties of pure water.
Databáze: OpenAIRE
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