Exploring improved hemodynamics in a stenosed artery using a two-phase Eulerian-granular blood model

Understanding the motion of red blood cells (RBCs) in stenosed blood vessels is critical for advancing knowledge of cardiovascular diseases such as atherosclerosis. This study employs a two-phase Eulerian-granular model to investigate hemodynamics in arteries with varying degrees of stenosis (DOS). By incorporating kinetic theory to account for RBC particle mechanics, the present model provides better predictive capabilities compared to single-phase Newtonian, non-Newtonian, and two-phase Euler–Euler models, showing better agreement with experimental data for straight arteries (0% DOS). The findings of this study reveal that stenosis significantly alters RBC distribution, deviating from the typical central plasma-surrounded configuration. The non-uniform RBC distribution in an artery significantly influences the corresponding velocity and vorticity fields, which again increases with the degree of stenosis. For instance, at 30% DOS, RBCs centralize more, while at 70% DOS, higher concentrations shift toward the proximal vessel wall. These changes again vary between the proximal and distal stenosed regions and across three different phases of the cardiac cycle, namely, acceleration (T1), peak systole (T2), and deacceleration (T3). Axial velocity profiles differ across the stenosed sections, with flow separation at 30% DOS and intensified recirculation at 70% DOS, both significantly influenced by cardiac phases. Turbulent kinetic energy (TKE) distribution is symmetric, peaking in T3 for 30% DOS and in T2 for 70% DOS. Area-averaged wall shear stress (AWSS) increases with DOS, particularly at the stenosis throat section. Furthermore, this study finds that the single-phase Newtonian model overpredicts flow separation and recirculation compared to the two-phase present approach. Overall, this study demonstrates the capability of the present two-phase model in capturing the impact of spatial RBC distribution on hemodynamics in stenosed arteries, offering potential extensions for the investigations of the hemodynamics of other complex biological systems.