Vortex Motion of Transitional Swirling Flows in a Rectangular Channel

Abstract

The purpose of this study is to make clear the behavior of the swirling pipe flows with non-circular section. Transitional swirling flows in a rectangular channel with aspect ratio of 1.3 and a short channel length, which is one of typical pipe flow with non-circular section, were investigated experimentally and numerically. In this experiment with water circulation flow, LDV measurement system was used in order to obtain the mean velocity fields and turbulent quantities. The flow visualization of the swirling flows was carried out in order to understand the oscillating motion of vortex core. Also, large eddy simulation of the flow fields was made at the same conditions as the experimental ones. As results of these investigations, the computational results showed good agreement with experimental ones quantitatively, it was found that the vortex core region moves to the swirling direction with deformation and interactions of secondary flow at the corners.