Transport Phenomena of Pulsatile Flow in a Curved Pipe.

Abstract

Pulsatile flow in a curved pipe enhances gas or substance transport because of the existence of secondary flows, and provides more mixing in the liquid phase than do steady flows. In this study, numerical analysis was performed on fully developed pulsating flow in a curved pipe under flow conditions similar to those characteristic of the blood flow in an aortic arch or in a booster lung. The calculations were performed over a wide range of Dean numbers De and Womersley numbers Wo for a fixed curvature ratio δ=0.05, and Schmidt number Sc=2900. The isodensity contour of the axial direction having a thin boundary layer near the wall was shown. Furthermore, it was revealed that the time- averaged Sherwood number (Sh)^^- increased by about 10 times due to the convection effect of secondary flows in the case of high Dean number flows compared with low Dean number flows, and that in the case of pulsatile flows, the time- averaged Sherwood number approached the values that of steady flows when the volumetric flow rate β equaled 10.