Multiple-component lattice Boltzmann equation for fluid-filled vesicles in flow.

Area of Science:

• Computational fluid dynamics
• Biophysics
• Soft matter physics

Background:

• Simulating deformable objects like vesicles is computationally challenging.
• Existing methods often require complex interface tracking and remeshing.
• Accurate modeling of vesicle mechanics in fluid flow is crucial for understanding biological and soft matter systems.

Purpose of the Study:

• To develop and implement an extended lattice Boltzmann equation (LBE) model for simulating vesicle dynamics.
• To create a computationally efficient Eulerian framework for coupled vesicle-fluid flow.
• To avoid explicit membrane tracking and reduce computational cost.

Main Methods:

• Extended a two-dimensional, multicomponent LBE model with Laplace law interfacial tension.
• Developed an Eulerian scheme representing vesicle membranes and fluid flow in a single framework.
• Implemented a model that inherently conserves vesicle volume and membrane length.

Main Results:

• The extended model accurately describes vesicle boundaries with conserved properties (volume, length, compressibility, bending rigidity, curvature, tension).
• The Eulerian approach eliminates the need for explicit interface tracking and remeshing.
• Validation data confirm the method's utility in simulating high volume fraction suspensions of deformable vesicles.

Conclusions:

• The developed LBE model provides an efficient and robust method for simulating vesicle dynamics in fluid flow.
• This approach significantly reduces computational expense compared to traditional interface tracking methods.
• The model is suitable for simulating complex systems involving deformable objects, such as suspensions.