Slip, immiscibility, and boundary conditions at the liquid-liquid interface.
The conventional boundary conditions at the interface between two flowing liquids include continuity of the tangential velocity. We have tested this assumption with molecular dynamics simulations of Couette and Poiseuille flows of two-layered liquid systems, with various molecular structures and interactions. When the total liquid density near the interface drops significantly compared to the bulk values, the tangential velocity varies very rapidly there, and would appear discontinuous at continuum resolution. The value of this apparent slip is given by a Navier boundary condition.
Koplik
Joel
J
Benjamin Levich Institute and Department of Physics, City College of the City University of New York, New York, New York 10031, USA. koplik@sci.ccny.cuny.edu
Banavar
Jayanth R
JR