Electronic Theses and Dissertations

Identifier

658

Date

2012

Document Type

Dissertation

Degree Name

Doctor of Philosophy

Major

Engineering

Concentration

Mechanical Engineering

Committee Chair

John I. Hochstein

Committee Member

Jeffrey Marchetta

Committee Member

Jiada Mo

Committee Member

Gladius Lewis

Abstract

Previous studies indicate that the likelihood of rate of restenosis following installation of a bare metal stent to treat coronary artery disease is related to the magnitude of the wall shear stress in the artery. The current study seeks to understand if including fluid-structure interaction (FSI) in a computational model of a stented coronary artery significantly influences the predicted wall shear stress on exposed patches of the artery. As a secondary result, it also determines influence of FSI on the magnitude of WSSon the surface of the stent. COMSOLMultiphysics was the computational tool selected for this study. It was carried out using rigid (no-FSI) and compliant wall (FSI)models comprising of a straight user-defined coronary artery, blood domain and a realistic stent. The arterial wall and stent were modeled as linear elastic materials while the blood was represented by an incompressible Newtonian fluid. Blood flow was assumed to be laminar and its boundary conditions were derived from published physiological waveforms. A periodic Womersley velocity profile was prescribed as the inflow boundary condition and a periodic pressure was prescribed as the outflow condition. Quasi-stationary analyses were carried out on both the rigid and compliant-wall models at different times. A mesh convergence study lead to a mesh-independent model. On comparing the FSIand no-FSImodels, it was concluded that the influence of FSIwas prominent on the stent surface and in the distal region of the geometric model. Although differences between model predictions of wall shear stress varied throughout the period of the waveform, the ranges of difference depend on the axial location along the artery: 10-20% in the proximal region, 17-55% in the distal region, 10-35% within the stent openings, and 16-58% on the stent surfaces.

Comments

Data is provided by the student.

Library Comment

Dissertation or thesis originally submitted to the local University of Memphis Electronic Theses & dissertation (ETD) Repository.

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