An experimental and theoretical study on the formation of Faraday waves in a viscous fluid

GASTON MIÑO; CECILIA CABEZA; SEBASTIAN UBAL; MARIA DELIA GIAVEDONI

Mar del Plata

Congreso; Pan-American Advanced Studies Institute (PASI) on Interfacial Fluid Dynamics: From Theory to Applications; 2007

UNIVERSIDAD DE BUENOS AIRES, UNIVERSIDAD NACIONAL DEL CENTRO DE LA PCIA.DE BS.AS, y NEW JERSEY INSTITUTE OF TECHNOLOGY (NJIT)

In this work we measured the conditions for the onset of Faraday waves (Faraday, 1831) on a liquid layer which is vibrated at a fixed frequency within the range 30 - 120 Hz. To minimize the influence of the lateral boundaries the experiments were carried out in two different types of cylindrical containers, one corresponding to the shelf conditions described by Bechhoefer el al (1995) and the other presenting a deeper region of constant depth at the border. The diameter of the central region was many wavelength large, and the dimensions of the lateral region were designed taking into account the following issues: a) the length of decay of capillary waves. In the containers employed the width of the bench was smaller or several times larger than the average capillary length. b) the wavelength of the expected waves. In the containers used, the width of the lateral boundaries was smaller or several times larger than the average wavelength. Liquid layers of Silicon oils of 50 and 100 cSt with depths equal to 2 and 15 mm were tested. In the thinnest layer the influence of the bottom wall was important while in the second one the opposite situation occurred. Measurements of the critical amplitude and wave numbers were compared with solutions of the linear stability analysis presented by Kumar and Tuckermand (1994). Also, the different patterns observed were compared with previously reported results (Kudrolli and Gollub, 1996; Westra et al, 2003).