Axisymmetric compact finite-difference lattice Boltzmann method for blood flow simulations

Area of Science:

• Computational fluid dynamics
• Biomedical engineering
• Fluid mechanics

Background:

• Simulating blood flow in arteries is crucial for understanding cardiovascular diseases.
• Existing methods face challenges in accurately modeling complex arterial geometries and non-Newtonian blood properties.

Purpose of the Study:

• To develop and validate an axisymmetric finite-difference lattice Boltzmann method for simulating Newtonian and non-Newtonian blood flow.
• To accurately resolve arterial curvature and incorporate blood rheology into flow simulations.

Main Methods:

• Developed an axisymmetric compact finite-difference lattice Boltzmann method with body-fitted mesh.
• Incorporated axisymmetric and non-Newtonian flow characteristics using source terms in the lattice Boltzmann equation.
• Verified the solver with steady and pulsatile flow simulations of Newtonian and non-Newtonian fluids in various lumen geometries.

Main Results:

• The method accurately resolves arterial curvature and recovers macroscopic hydrodynamic equations.
• Simulations showed reduced recirculation zones and lower wall shear stress (WSS) for non-Newtonian fluids in stenosed lumens compared to Newtonian fluids.
• Analysis of pulsatile flow in an abdominal aortic aneurysm revealed critical WSS gradients associated with rupture risk.

Conclusions:

• The proposed lattice Boltzmann method is a promising tool for simulating axisymmetric blood flow with steady and pulsatile inflows.
• The solver effectively accounts for blood rheology and complex flow dynamics in arterial models.
• This method can aid in the diagnosis and treatment planning for vascular diseases.