Shear-thickening induced by Faraday waves in dilute wormlike micellesP. Ballesta and S. Manneville
Centre de Recherche Paul Pascal - Avenue Schweitzer, 33600 Pessac, France
received 27 July 2006; accepted in final form 15 September 2006
published online 11 October 2006
We investigate the effect of surface waves generated by the Faraday instability on a shear-thickening surfactant solution under vertical vibrations. We show that a prolonged oscillation of the surface above the instability onset leads to an increase of the fluid viscosity. This phenomenon is evidenced by comparing the time needed for the instability to develop in the fluid at rest and once the fluid has been shaken above onset: pre-shaking may delay the instability by two orders of magnitude. A simple model based on a time-dependent viscosity is proposed which accounts quantitatively for the experimental observations.
47.50.-d - Non-Newtonian fluid flows.
47.20.-k - Flow instabilities.
83.60.Rs - Shear rate-dependent structure (shear thinning and shear thickening).
© EDP Sciences 2006