A comparison of steady and pulsatile flow in symmetrically branched tubes

The purpose of this study was to compare the characteristics of flow in the region of symmetrical bifurcations having branch-to-trunk area ratios of 0.4, 0.8 and 1.2 during steady and pulsatile flow. Flow was visualized with neutrally bouyant particles. Secondary flow was not observed in the branches during either steady or pulsatile flow when the branch-to-trunk area ratio was 0.4. Secondary velocity patterns were not observed in the branches with branch-to-trunk area ratios of 0.8 and 1.2 during pulsatile flow, although they were observed during steady flow. It may be inaccurate, therefore, to characterize pulsatile flow at an instantaneous Reynolds number on the basis of steady flow at the same Reynolds number.