Computational And Analytical Study of Hybrid Nano-Blood Flow in Curved and Bifurcated Stenosed Arteries with Eccentric Catheterization

The subject of the blood flow in stenosed arteries has attracted a lot of interest in the development and progression of cardiovascular diseases, especially when they are affected by complex arterial geometry, catheterization, and advanced therapeutic agents like nanoparticles. The phenomenon of stenosis, which is the abnormal constriction of the arterial lumen under the influence of the deposition of atherosclerotic plaques, has a significant impact on the main parameters of hemodynamics such as velocity profiles, pressure gradient, wall shear stress, and resistance to flow. Catheterization is used extensively in clinical practice, both diagnostically and therapeutically, but when a catheter is inserted, it establishes an annular flow field within the artery resulting in significant changes in the flow behavior and pressures than in non-catheterized vessels. This thesis includes a thorough mathematical and computational exploration of unsteady pulsatile blood flow in stenosed arteries in physiologically realistic conditions. Curved and bifurcated arterial geometries with single, multiple and overlapping stenosis and catheterized geometries are all included in the analysis. Blood is simulated using the non-Newtonian, fractional-order viscoelastic fluid models as well as the Newtonian fluid models to effectively explain the shear-thinning, memory-dependent and viscoelastic properties of blood. Moreover, blood is considered a nanofluid by introducing metallic and hybrid nanoparticles, which makes it possible to study any alteration in thermal conductivity, viscosity, and general hemodynamic reaction caused by nanoparticles. The equations of governing continuity, momentum and energy are developed in suitable curvilinear coordinate frames to take into consideration the curvature of the arteries and their geometric complexities. Mathematical and numerical methods of solutions such as perturbation and explicit finite difference methods are used with mild, moderate and severe stenotic conditions. An extensive parametric study is carried out in order to determine the impact of the severity of stenosis, arterial curvature, bifurcation angle, catheter size, catheter position, nanoparticle volume fraction, effects of heat transfer, and fractional rheological parameters on velocity distribution, temperature field, catheter wall shear stress, resistance to flow and volumetric flow rate. Findings indicate that arterial curvature, the degree of stenosis and catheter existence have significant impacts on the amplification of the hemodynamic disturbances, causing rise in resistance and changes in the pressure as well as stress distributions. Due to the integration of nanoparticles, the thermal control and alteration of flow properties are improved, and more pronounced effects are observed with hybrid and higher-order nanoparticles. The questions of the given research lead to the greater comprehension of the catheterized nano-blood flow in the stenosed arteries and contribute to the theoretical background of the better cardiovascular diagnostic, the development of the targeted drug delivery plans, and the designing of the novel biomedical devices.