Effect of surface roughness on slip flows in hydrophobic and hydrophilic microchannels by molecular dynamics simulation
| Autor: | S. C. Yang, L. B. Fang |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
musculoskeletal diseases
Quantitative Biology::Biomolecules Materials science General Chemical Engineering General Chemistry Slip (materials science) Condensed Matter Physics Volumetric flow rate Condensed Matter::Soft Condensed Matter Physics::Fluid Dynamics Shear rate Molecular dynamics Modeling and Simulation Surface roughness No-slip condition General Materials Science Boundary value problem Slip ratio Composite material Information Systems |
| Zdroj: | Molecular Simulation. 31:971-977 |
| ISSN: | 1029-0435 0892-7022 |
| DOI: | 10.1080/08927020500423778 |
| Popis: | The influences of surface roughness on the boundary conditions for a simple fluid flowing over hydrophobic and hydrophilic surfaces are investigated by molecular dynamics (MD) simulation. The degree of slip is found to decrease with surface roughness for both the hydrophobic and hydrophilic surfaces. The flow rates measured in hydrophobic channels are larger than those in hydrophilic channels with the presence of slip velocity at the walls. The simulation results of flow rate are correlated with the theoretical predictions according to the assumption of no slip boundary condition. The slip boundary condition also strongly depends on the shear rate near the surface. For hydrophobic surfaces, apparent fluid slips are observed on smooth and rough surfaces. For simple fluids flowing over a hydrophobic surface, the slip length increases linearly with shear rate for both the smooth and rough surfaces. Alternately, the slip length has a power law dependence on the shear rate for the cases of hydrophilic surfaces... |
| Databáze: | OpenAIRE |
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