Wall shear stress and flow stability in a model fusiform aneurysm

Abstract

Levels of wall shear stress in arterial blood flow are known to contribute to the integrity of wall tissue, and are believed to have a bearing on the pathogenesis of aneurysm disease. The flow of fluid through a model aneurysm was computed using a spectral element algorithm to study the distribution of wall shear stress and the stability of the flow to non-axisymmetric perturbations. Substantially higher mean and fluctuating wall shear stress components were found in the distal (downstream) region of the aneurysm bulge when compared to recent experimental measurements. A global stability analysis demonstrates that flow conditions consistent with a human aorta will produce non-axisymmetric flow in an aneurysm consistent with that modeled here. These results demonstrate the necessity for detailed numerical modeling of these flows to accurately resolve the near wall fluid stresses. References

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