A comparative study of rheological effects of blood flow in a stenosed artery using non-Newtonian model

Blood flow is non-Newtonian and rheological behaviour is important for evaluating the hemodynamic environment in stenosed arteries. This study compares pulsatile blood flow through a mildly tapered and mildly stenosed artery using four widely used non-Newtonian fluid models, namely the Power-Law, Herschel-Bulkley, Casson and Carreau models. Blood is assumed to be an axisymmetric, unsteady fluid and the basic model equations are solved numerically under a periodic pressure gradient using a finite difference scheme. The effects of blood rheology on axial and radial velocities, volumetric flow rate, flow resistance and wall shear stress are systematically examined. The analysis shows that the Power-Law model yields the highest axial velocity and the greatest volumetric flow rate, whereas the Casson model produces the largest flow resistance. Moreover, the maximum wall shear stress occurs at the stenosis throat because the velocity gradients are enhanced at the arterial constriction. The study shows that blood rheology, vessel tapering, and pulsatile flow behavior together determine the hemodynamic behavior of diseased arteries. The results are useful for understanding the progression of arterial disease, developing patient-specific hemodynamic assessment, and designing cardiovascular diagnostic and therapeutic approaches.