Computational and Experimental Study of Hemodynamics in Abdominal Aortic Aneurysms
An abdominal aortic aneurysm (AAA) is a localized dilation of the abdominal aorta resulting from the weakening of the aorta wall. Most of the human AAA's harbor an intraluminal thrombus. However, its role in AAA progression is unclear and hence, it is important to understand the role of hemodynamics in thrombus formation. A detailed literature survey on phantom fabrication, in-vitro flow loop setup, and CFD studies indicated that intense research activity is pursued currently to evolve strategies for better diagnosis and surgical interventions. In this thesis work, a procedure for aneurysm phantom fabrication was standardized and experimentally demonstrated by adopting a 2-axis rotation coating method. Further, an in-vitro mock circulatory flow loop was designed and tested. Through image-based computational fluid dynamics studies, the reason for thrombus initiation and deposition was explored through the study of near-wall quantities such as time-averaged wall shear stress, oscillatory shear index, endothelial cell activation potential, and residence time. The various hemodynamic quantities well-predicted the region of thrombus initiation and deposition due to the high residence time and hot spots of Endothelial Cell Activation Potential observed in the actual site of thrombus deposition in the patient.