Prediction of fluid velocity slip at solid surfaces

Area of Science:

• Fluid dynamics
• Computational physics
• Materials science

Background:

• Fluid flow enhancement in confined geometries is often attributed to velocity slip at solid-fluid interfaces.
• Existing methods for predicting slip can be complex or rely on empirical parameters.

Purpose of the Study:

• To introduce a simple and accurate method for predicting fluid velocity slip using equilibrium molecular dynamics.
• To directly compute the intrinsic wall-fluid friction coefficient.

Main Methods:

• Utilized equilibrium molecular dynamics (EMD) simulations.
• Developed a novel approach to directly calculate the intrinsic wall-fluid friction coefficient.

Main Results:

• The proposed EMD method accurately predicts fluid slip length.
• Results show excellent agreement with nonequilibrium molecular dynamics (NEMD) simulations.
• The method bypasses the need for empirical friction coefficients.

Conclusions:

• The new EMD method provides a direct and accurate way to quantify wall-fluid friction and predict slip length.
• This advancement offers a more fundamental understanding of fluid behavior in confined systems.
• The method has implications for designing microfluidic devices and understanding interfacial phenomena.