The onset of Faraday waves at a liquid – liquid interface containing an insoluble surfactant

SEBASTIÁN UBAL; MARÍA D. GIAVEDONI

Punta del Este, Uruguay

Conferencia; XVI Conference on non equilibrium statistical mechanics & non linear physics (Medyfinol’08); 2008

The formation of Faraday waves is a parametric instability first observed by Faraday (1831) when he immersed a vibrating plate in water. Specifically, he noted the formation of suharmonic standing waves on the surface of the liquid.Benjamin and Ursell (1954) provided an explanation for this phenomenon, in the particular case in which the liquid is inviscid and its motion can be regarded as irrotational.Since then, a large number of studies have been published regarding different aspects of the problem (see, for instance the review by Henderson and Miles, 1990), most of them concerned with the formation of the waves when the upper fluid is air.The effects of adding a second immiscible fluid were analyzed theoretically by Kumar and Tuckerman (1994) and by Hill (2002); numerically and just for the particular case of inviscid fluids by Wright el al (2000), and experimentally by Tipton and Mullin (2004).Hereby, we extend the analysis of Kumar and Tuckerman by including the effects of an insoluble surfactant on the critical conditions for the formation of Faraday waves between two immiscible, viscous fluids.