Graduate Studies

 

Date of this Version

7-2011

Comments

A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of the Requirements For the Degree of Master of Science, Major: Mechanical Engineering, Under the Supervision of Professor Linxia Gu. Lincoln, Nebraska: July, 2011

Copyrigt 2011 Ying Han

Abstract

Aortic coarctation is a narrowing on aorta, which accounts for 5-8% of the congenital heart defects. Symptoms, which could lead to problems threatening to patients’ life, depend on the severity of coarctation. Mechanical stress plays important roles in the function of the cardiovascular system, and blood flow has been an interesting topic to both engineers and clinicians from early days to investigate the possibility that certain blood flow patterns involved in the development of vascular disease. Fluid-structure interaction (FSI) analysis is a useful tool to understand the principles of the coarctaion, which can potentially be used to identify major risk factors and improve the treatment strategy. This study has presented both constant and pulsatile blood flows in the coarctate artery through integrated FSI modeling techniques. Finite element (FE) models based on two simulation techniques, -i.e. coupled Eulerian- Lagrangian (CEL), as well as computational fluid dynamics (CFD)/ structure co-simulation, are developed. As validation, results from computational model are compared with analytical solution as well as in vitro experiment of laminar flow through latex tube carried out with ARAMIS high speed camera to capture the tube deformation. Reasonable outcomes are obtained according to the comparisons. Effects of coarctation severity, material compliance, and grafting treatment are evaluated. Results are consistent with clinical findings, indicating the computational model could be used to interpret clinical observations, predict flow/wall behavior under certain condition, help evaluate and make decisions of the choice of treatment.

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