A homogenized two-phase computational framework for meso- and macroscale blood flow simulations

Area of Science:

• Computational fluid dynamics
• Biomedical engineering
• Hemodynamics

Background:

• Modeling blood flow is crucial due to its complex rheology.
• Existing computational fluid dynamic models face challenges with scalability when incorporating thrombosis and embolization.
• A need exists for computationally efficient blood flow models that retain high flow resolution.

Purpose of the Study:

• To present a homogenized two-phase blood flow framework.
• To develop a model with single-fluid characteristics but two-fluid resolution.
• To validate the framework against experimental data.

Main Methods:

• Utilized a classical diffusion-flux framework for computational efficiency.
• Proposed a modified slip velocity equation derived from two-fluid governing equations.
• Incorporated new hematocrit-dependent expressions for drag and lift forces on red blood cells (RBCs).
• Discretized and solved equations using OpenFOAM.

Main Results:

• Validated the framework against four distinct experimental setups.
• Demonstrated accurate prediction of RBC velocity profiles and hematocrit distributions in microchannels.
• Showcased good agreement with experimental data for cell-free layer thickness and hematocrit contours.
• Successfully predicted experimental hematocrit distributions in a left ventricular assist device-mimicking channel.

Conclusions:

• The developed framework efficiently models multiscale blood flow physics.
• It leverages numerical techniques suitable for single-phase flow simulations.
• The model is well-suited for complex applications like thrombosis and embolization studies.