الفهرس 
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Abstract
Cardiovascular diseases have become among the common diseases in the last few decades. In this study, predictions of blood flow patterns in the abdominal aortic aneurysms are performed in a two-dimensional Cartesian arterial segment with two aneurysms using computational fluid dynamics. The novelty of this study is considering the blood viscoelasticity using the Oldroyd-B model for the blood flow simulation. Blood flow is considered as an incompressible viscoelastic fluid through a rigid planar channel. One of the most challenging numerical problems is the incompressibility constraint. The continuity equation is modified by adding a Laplacian term of the pressure to overcome the pressure spurious oscillations. The proposed technique has another advantage which is using equal-order interpolation functions for all variables. Also the proposed technique is proven to be equivalent to the artificial compressibility method for steady flow case with lower computational costs. The Galerkin least squares finite element method (GLSFEM) is used for numerical solution of the governing equation. The DEVSS method is used to overcome the instabilities resulting from the numerical solution of the viscoelastic flow model. Results are obtained for benchmark problems such as the lid-driven cavity flow and the flow around a circular cylinder. The results are compared with published works for the purpose of the code validation and then results are obtained for the main blood flow problem under realistic flow conditions. The results show that the wall shear stress and the wall pressure for viscoelastic simulation have higher values than those of Newtonian simulation. Therefore, the blood viscoelasticity should not be ignored especially at low shear rates. The results indicate that the aneurysm zones are the zones which are mostly subjected to the risk of the atherosclerosis because the wall shear stress has its minimum values.