Molecular dynamics validation of shear-dependent nonlinear slip boundary condition for water

The classical no-slip boundary condition has long served as a foundational assumption in continuum fluid mechanics; however, it is known to break down in microscale and high-shear flows where interfacial slip becomes significant. Nonlinear slip models proposed by Thompson and Troian, and later generalized by Thalakkottor and Mohseni, demonstrated that slip length is not constant but increases nonlinearly with shear rate. Previous validations of these models have primarily relied on monatomic Lennard-Jones (LJ) fluids, limiting their applicability to realistic liquids. In this study, non-equilibrium molecular dynamics simulations are performed to investigate the validity of the nonlinear slip boundary condition for transferable intermolecular potential with 3 points water confined by LJ walls. Three liquid–solid interfaces with different wall–water interaction parameters are examined under Couette flow conditions, and published Extended Simple Point Charge water data for graphene nanochannels are analyzed as an independent comparison. The results demonstrate that water exhibits the same nonlinear slip behavior previously observed in simple LJ fluids. In addition, this nonlinear behavior can be described by the same universal scaling relationship proposed by Thompson and Troian. These findings extend the applicability of nonlinear slip models to commonly encountered fluids such as water.