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Full-Text Articles in Mechanical Engineering
Effect Of Surface Roughness On Rate-Dependent Slip In Simple Fluids, Nikolai V. Priezjev
Effect Of Surface Roughness On Rate-Dependent Slip In Simple Fluids, Nikolai V. Priezjev
Mechanical and Materials Engineering Faculty Publications
Molecular dynamics simulations are used to investigate the influence of molecular-scale surface roughness on the slip behavior in thin liquid films. The slip length increases almost linearly with the shear rate for atomically smooth rigid walls and incommensurate structures of the liquid/solid interface. The thermal fluctuations of the wall atoms lead to an effective surface roughness, which makes the slip length weakly dependent on the shear rate. With increasing the elastic stiffness of the wall, the surface roughness smoothes out and the strong rate dependence is restored again. Both periodically and randomly corrugated rigid surfaces reduce the slip length and …
Rate-Dependent Slip Boundary Conditions For Simple Fluids, Nikolai V. Priezjev
Rate-Dependent Slip Boundary Conditions For Simple Fluids, Nikolai V. Priezjev
Mechanical and Materials Engineering Faculty Publications
The dynamic behavior of the slip length in a fluid flow confined between atomically smooth surfaces is investigated using molecular dynamics simulations. At weak wall-fluid interactions, the slip length increases nonlinearly with the shear rate provided that the liquid/solid interface forms incommensurable structures. A gradual transition to the linear rate-dependence is observed upon increasing the wall-fluid interaction. We found that the slip length can be well described by a function of a single variable that in turn depends on the in-plane structure factor, contact density and temperature of the first fluid layer near the solid wall. Extensive simulations show that …