Changes in flow and wall stresses through arterial constrictions offset from the centre of the vessel

Abstract

Blood flow through small, obstructed vessels is studied by computing flows in tubes featuring three dimensional sinusoidal constrictions. A high order spectral element algorithm determines the extent of physiological flow characteristics such as recirculation zones and wall shear stress (WSS). Comparisons find that an increase in constriction eccentricity gives rise to more intense WSS. Moreover, these irregular flow conditions persist further downstream. Consistently, shear rate increases with Reynolds number and constriction eccentricity. Vorticity perpendicular to the constriction geometry and shear rate both increase with blockage ratio. In axisymmetric geometries, dissipation of the shear layers associated with downstream recirculation occurs more quickly. With larger constriction eccentricities, zones of high WSS are found on the far wall downstream of the constriction. This could lead to degradation of the wall tissue. References

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