Diffusion coefficient of Brownian particle in rough micro-channel

Area of Science:

• Physics
• Computational Science

Background:

• Brownian motion is fundamental to understanding particle transport in fluids.
• Surface characteristics significantly influence particle dynamics in confined geometries.

Purpose of the Study:

• To investigate the impact of surface roughness on Brownian particle diffusion coefficients.
• To explore the feasibility of the lattice Boltzmann method for simulating these effects.

Main Methods:

• Utilized the lattice Boltzmann method for fluid dynamics simulation.
• Represented channel surface roughness using a regular array of spheres.
• Analyzed changes in the velocity autocorrelation function and pressure.

Main Results:

• Surface roughness was found to decrease the diffusion coefficient of Brownian particles.
• This reduction is linked to alterations in velocity autocorrelation function decay and pressure.
• Increased particle proximity enhanced the diffusion coefficient.

Conclusions:

• The lattice Boltzmann method is a viable tool for studying surface roughness effects on diffusion.
• Surface roughness acts as a barrier, hindering Brownian particle movement.
• Inter-particle interactions can counteract surface-induced diffusion reduction.