Nonlinear generation of vorticity in thin smectic films1)
V. M. Parfenyev2), S. S. Vergeles, V. V. Lebedev
Landau Institute for Theoretical Physics of the RAS, 142432 Chernogolovka, Russia
Abstract
We analyze a solenoidal motion in a vertically vibrated freely
suspended thin smectic film. We demonstrate analytically that transverse
oscillations of the film generate two-dimensional vortices in the plane of
the film owing to hydrodynamic nonlinearity. An explicit expression for the
vorticity of the in-plane film motion in terms of the film displacement is
obtained. The air around the film is proven to play a crucial role, since it
changes the dispersion relation of transverse oscillations and transmits
viscous stresses to the film, modifying its bending motion. We propose
possible experimental observations enabling to check our predictions.