Computational hemodynamic simulation of non-Newtonian fluid-structure interaction in a curved stenotic artery

This paper focuses on deploying Computational Fluid Dynamics (CFD) and Fluid-Structure Interaction (FSI) to investigate key characteristics associated with Cardiovascular Diseases (CVDs), a leading cause of global mortality. CVDs encompass various heart and blood vessel disorders, including coronary artery disease, stroke and atherosclerosis, which significantly impact arteries. Risk factors such as high blood pressure and obesity contribute to atherosclerosis, which is characterized by narrowed arteries due to fatty deposits, impeding blood flow and increasing heart attack and stroke risks. To simulate blood flow behaviour and its effects on artery stenosis formation, ANSYS-based CFD and monolithic (one-way) Fluid-Structure Interaction (FSI) analyses are deployed in this work. Extensive visualization of blood flow patterns relevant to patient-specific conditions is included using the non-Newtonian (Carreau shear-thinning) bio-rheological model. These simulations start with creating a three-dimensional patient artery model, followed by applying CFD/FSI methodologies to solve the equations iteratively with realistic boundary conditions. Velocity, pressure, wall shear stress (WSS), Von mises stress and strain characteristics are all computed for multiple curvature cases and different stenotic depths. Factors such as blood viscosity, density and its non-Newtonian behaviour due to red blood cells are considered. FSI analysis extends CFD by including the interaction between blood flow and deformable (elastic) arterial walls, accounting for the arterial mechanical properties and the flow-induced pressure changes. Here we do not consider the two-way case where deformation in turn affects the flow, only the one-way (monolithic) case where the blood flow distorts the arterial wall. This approach allows for deeper insight into the interaction between rheological blood flow and elastic arterial walls which aids in highlighting high stress zones, recirculation and hemodynamic impedance of potential use in identifying rupture or plaque formation, contributing significantly to the management and prevention of CVDs.