NUMERICAL ANALYSIS OF ANEURYSM USING PULSATILE BLOOD FLOW THROUGH A LOCALLY EXPANDED VESSEL

A numerical analysis based on a finite volume approach is employed for a 2-D axisymmetric, incompressible, laminar and transient flow in order to simulate the pulsatile blood flow in aneurysm. The unsteady nature of the blood is studied for three Womersley numbers and for three rheological models including Newtonian, Power law and Quemada. A physiological flow input waveform is presented in terms of Fourier series obtained by curve fitting to the experimental data. Introducing the hemodynamic wall parameters including wall shear stress (WSS), wall shear stress gradient (WSSG) and oscillatory shear index (OSI), results are presented for the variation of these parameters for all rheological models at different Womersley numbers. In addition, the effects of the rheological models and the Womersley number on the formation, growth, and shedding of the vortexes in the aneurysm are studied. The results implicates that the Womersley number has a significant effect on the flow field, while the effect of rheological model on the flow pattern is negligible. Besides, the reattachment and separation points are recognized based on the OSI and WSS diagrams.

Aneurysm, Pulsatile Flow, Numerical Analysis, non-Newtonian, Waveform