Flow characteristics in symmetrically branched tubes simulating the human aortic bifurcation.

The purpose of this study was to investigate the characteristics of flow in a symmetrically branched tube that had an area ratio (0.8) and angle of branching (70 deg) that were comparable to the human descending aorta. Velocity profiles were measured in steady and pulsatile flow with a laser Doppler anemometer. A region of transient flow reversal was found along the outer wall during minimal flow in the pulsatile cycle. Flow separation did not occur. For both steady and pulsatile flow, the shear rates were higher along the inner wall and lower along the outer wall in the region of the vertex of the bifurcation.