Kinetic alpha effect in viscosity stratified creeping flows

Abstract

It is shown that viscosity stratified plane Poiseuille flow may exhibit a long-wavelength instability of a purely kinetic nature formally resembling the so-called alpha effect known in magnetohydrodynamics or in anisotropic three-dimensional flows of homogeneous fluids. In the absence of the alpha effect, the system may display a peculiar type of long-wavelength instability, where the latter is controlled by the surface tension. The weakly nonlinear equation for the evolving interfaces is derived and solved numerically.