  We consider a meniscus between rotating and nonrotating species in the
Bose-Einstein condensate (BEC) with repulsive inter-atomic interactions,
confined to a pipe-shaped trap. In this setting, we derive a system of coupled
one-dimensional (1D) nonpolynomial Schrodinger equations (NPSEs) for two
mean-field wave functions. Using these equations, we analyze the phase
separation/mixing in the pipe with periodic axial boundary conditions, i.e. in
a toroidal configuration. We find that the onset of the mixing, in the form of
suction, i.e., filling the empty core in the vortical component by its
nonrotating counterpart, crucially depends on the vorticity of the first
component, and on the strengths of the inter-atomic interactions.
