Investigating the Effect of Different Rheological Models on the Blood Flow in Capillary Segments

Abstract

This study outlines the effect of applying different rheological blood flow models in capillaries. As there is no single, universally accepted computational model of the human blood flow, different approaches are investigated.

In this work, three-dimensional confocal microscopy image of a capillary segment will be modeled and analyzed using ANSYS Fluent. Three different models were investigated: Newtonian model, a non-Newtonian Carreau model and an empirical relation. The first model had a constant viscosity throughout the segment. The second model accounted for the shear thinning behavior of blood using the Carreau model. The last model was an empirical relation that relates the relative apparent viscosity of the blood to the tube diameter and the blood hematocrit.

The 3D, steady, laminar, single-phase Newtonian and non-Newtonian flow models are used to investigate the blood flow through the micro-vessel segment. The simulation results are evaluated to understand the outcomes of using the aforementioned modeling approaches.

It has been found that the pressure drop was the foremost result as it exhibits a noticeable difference between the models. On the other hand, changing the model has a minor impact on the results of the velocity and vorticity. It was also noticed that increasing the hematocrit value, even by a small percentage, leads to a noticeable increase in the pressure drop.