Comparison between a generalized Newtonian model and a network-type multiscale model for hemodynamic behavior in the...

Area of Science:

• Biomedical Engineering
• Computational Fluid Dynamics
• Rheology

Background:

• Blood rheology is complex and non-Newtonian, influenced by cellular components.
• Accurate modeling of blood flow is crucial for understanding cardiovascular health.
• Existing Newtonian and generalized Newtonian models have limitations in capturing blood's viscoelasticity.

Purpose of the Study:

• To implement and validate the Modified Phan-Thien Tanner (MPTT) viscoelastic model for blood flow simulation.
• To assess the MPTT model's performance against Newtonian and generalized Newtonian models.
• To investigate the impact of red blood cell viscosity on blood flow dynamics in the thoracic aorta.

Main Methods:

• Developed a patient-specific model of the thoracic aorta using medical imaging.
• Implemented the MPTT rheological model in OpenFOAM for numerical simulations.
• Utilized a 3-element Windkessel model with calibrated parameters for outflow boundary conditions.
• Compared simulation results with 4D MRI data and other rheological models.

Main Results:

• The MPTT model demonstrated superior agreement with in vivo 4D MRI data compared to Newtonian and generalized Newtonian models.
• Simulations captured blood flow and wall shear stress (WSS) variations during systolic and diastolic phases.
• The study analyzed the influence of red blood cell viscosity on flow characteristics.

Conclusions:

• The MPTT viscoelastic model provides a more accurate representation of blood flow in the thoracic aorta than simpler models.
• This advanced modeling approach is valuable for understanding hemodynamics in healthy individuals.
• The findings support the use of complex viscoelastic models for clinical applications.