Apparent hydrodynamic slip induced by density inhomogeneities at fluid-solid interfaces

This study demonstrates that even when the no-slip condition is satisfied on the surface of a solid wall, apparent hydrodynamic slip can be clearly seen owing to a continuous variation of viscosity associated with density inhomogeneity near the wall. The relationship between the apparent slip length and the local fluid properties, such as viscosity and/or density, has been established theoretically. The apparent slip length depends on the flow type and three cases are considered: shear-driven flow, body force-driven flow, and flow driven by external force acting on adsorbed solutes. Particle-based simulations have been performed and the consistency between our theory and the simulation has been verified.