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| Numerical analysis of hemodynamics in curved arteries |
| Revised:December 02, 2001 |
| View Full Text View/Add Comment Download reader |
| DOI：10.7511/jslx20032032 |
| KeyWord:curved artery,pulsatile flow,numerical analysis,nonlinear |
| Qiao Aike \ Liu Youjun \ Wu Shigui |
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| Abstract: |
| Numerical analysis according to the theories and methods of computational fluid dynamics (CFD) is one of the effective methods studying the hemodynamic mechanisms of cardiovascular disease in curved arteries. The ascending aorta, the aortic arch and the descending aorta are considered together as the geometric model. The boundary conditions and calculation conditions are proposed. The numerical simulation of the developing blood flow in the geometric model of dogs is carried out with finite element method (FEM) according to the physiologically pulsatile flow conditions. The initial\|boundary conditions include: non\|slip conditions on the wall, symmetric conditions in the symmetric plane, physiological pulsatile entrance velocity and outlet pressure conditions. Several pulsation periods of calculation are performed to obtain the final convergent results. The calculation results of blood flow such as the axial velocity, secondary flow, wall shear stress and pressure wave are analyzed with scientific visualization method. Their temporal\|spatial distributions are intuitively shown with a lot of 2\|d and 3\|d figures. The research results indicate there are simultaneous reversed flows in the main flow and the secondary flow directions in the inner bend where vortex is prone to occur. Reversed flows are mainly located in the downstream area and closely related to the increase and decrease of entrance velocity. With the propagation of pressure wave to the downstream along the centerline the dicotism weakens gradually and the pressure wave becomes steep gradually. The magnitude and variation range of wall shear stresses in the inner bend of the aortic arch are much larger than those in the outer bend. The endothelium cells in the inner bend are much easier to suffer from oxygen lack caused by vortex and be injured by alternative wall shear stresses. The injury of endothelium has serious relationship with the growing and developing of lipopexia and atherosclerosis. |
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