Boundary conditions for fluids with internal orientational degrees of freedom: Apparent velocity slip associated with the molecular alignment

摘要: Boundary effects are investigated for fluids with internal orientational degrees of freedom such as molecular liquids, thermotropic and lyotropic liquid crystals, polymeric fluids. The described by the second rank alignment tensor which is related to birefringence. We use a standard model describe dynamics in presence flow, momentum balance equations, constitutive law pressure our system. In spirit irreversible thermodynamics, boundary conditions formulated mechanical slip velocity flux alignment. They set up that entropy production at wall inferred from positive definite. Even absence true slip, coupling between orientation flow leads profiles an apparent slip. This has consequences macroscopically measurable effective velocity. analytical investigations, we consider simplified case isotropic fluid Newtonian stationary regime. For special geometries plane cylindrical Couette Poiseuille down inclined plane, demonstrate explicitly how lead Furthermore, discuss dependence viscosity length on parameters.