Effects of waveform shape of pulsatile blood flow on hemodynamics in an artery bifurcation model

Abstract

Pulsatile non-Newtonian fluid flow was simulated in an artery bifurcation model, with three different inlet flow waveform shapes and an identical inlet mean velocity steady-state condition, to quantify the impact of three different waveform shapes on hemodynamics such as flow patterns, wall shear stress, and oscillatory shear index during a cardiac cycle. It was found that the degree of flow separation is insensitive to changes in flow waveform shape. There is remarkable similarity in the position and magnitude of the maximum wall shear stress at peak systole and the maximum time-averaged wall shear stress for all examined cases. The oscillatory shear index distributions are broadly similar except that the local maximum oscillatory shear index increases proportionally with the pulsatility index of the waveform shape. The maximum oscillatory shear index values on the planar branch are within 8.7% in all examined cases, while these oscillatory shear index values on the nonplanar branch are identical due to the effects of its curvature. The negligible hemodynamic differences between simplified and characteristic waveform cases suggest that changes in waveform shape play a minimal role in the progression and development of atherosclerosis. Although the computed hemodynamics is almost consistent for the three different waveform shapes, several slight differences were observed.