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Equilibrium measurement method of slip length based on fluctuating hydrodynamics
Hiroyoshi Nakano1, Shin-Ichi Sasa1
1Department of Physics, Kyoto University, Kyoto 606-8502, Japan.
Physical Review. E
|April 16, 2020
Summary
Molecular dynamics simulations reveal linearized fluctuating hydrodynamics accurately describes nanoscale fluid force fluctuations. This provides a method for estimating fluid slip length on smooth surfaces.
Area of Science:
- Fluid dynamics
- Statistical mechanics
- Nanoscale science
Background:
- Understanding fluid behavior at the nanoscale is crucial for various applications.
- Slip length quantifies fluid-wall interactions, impacting flow dynamics.
- Autocorrelation functions provide insights into dynamic processes.
Purpose of the Study:
- To investigate the relationship between force autocorrelation functions and slip length in confined nanoscale fluids.
- To validate linearized fluctuating hydrodynamics (LFH) against molecular dynamics simulations for nanoscale fluids.
- To establish LFH as a tool for estimating slip length.
Main Methods:
- Equilibrium molecular dynamics simulations of nanoscale fluids confined between parallel walls.
- Analysis of the autocorrelation function of forces acting on the walls.
- Comparison of simulation results with theoretical predictions from LFH.
Main Results:
- The autocorrelation function of wall forces is accurately described by LFH for atomically smooth surfaces.
- Excellent agreement between simulation and LFH was observed across a wide range of timescales.
- Slip length can be reasonably estimated by fitting simulation data to LFH.
Conclusions:
- LFH accurately models nanoscale fluid dynamics and force fluctuations.
- The study establishes a connection between force fluctuations and slip length.
- LFH serves as a valuable framework for further research into fluid-wall interactions.
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