Modified momentum exchange method for fluid-particle interactions in the lattice Boltzmann method

Area of Science:

• Computational fluid dynamics
• Multiphase flow modeling

Background:

• Traditional fluid-particle interaction models face limitations with boundary point placement.
• Accurate simulation of particle dynamics is crucial in various engineering applications.

Purpose of the Study:

• To propose a modified momentum exchange method for fluid-particle interactions.
• To overcome limitations of existing methods regarding boundary conditions.
• To accurately simulate particle motion, especially when particle and fluid densities are similar.

Main Methods:

• Finite-volume lattice Boltzmann method (FV-LBM) with a modified momentum exchange approach.
• Particle surface represented by arc (area) elements, satisfying geometric conservation law.
• Numerical integration for fluid-particle mass exchange and smooth kernel function for fluid field correction.
• Generalized explicit time marching scheme for particle motion analysis.

Main Results:

• The improved method removes restrictions on boundary point placement.
• Accurate calculation of fluid-particle momentum and mass exchange.
• Successful simulation of particle sedimentation with density ratios close to or less than 1.
• Numerical results show good agreement with existing literature.

Conclusions:

• The modified momentum exchange method provides a robust and accurate approach for fluid-particle simulations.
• The method is particularly effective for scenarios involving low density ratios.
• Validated by particle sedimentation cases, demonstrating its capability and reliability.