Reynolds Number and Geometry Configuration Effect on Secondary Flows in S-Shaped Circular Bends

O. Ayala [1], M. F. Degenring Oliveira [2], P. Loures [2],
[1] Department of Engineering Technology, Old Dominion University, Norfolk, VA, USA
[2] Brazil Scientific Mobility Program, CAPES, Brasilia DF, Brazil
Published in 2016

Reynolds Numbers effect: In the first bend, the higher the Reynolds number, the longer the first pair of vorticities stays attached to the wall. In the second bend, the higher Reynolds Numbers, the secondary flow from the first bend dominates.

Curvature Radius effect: The smaller the curvature radius is, the stronger the vorticity magnitude is, and longer it will take for the second pair of secondary flows to develop.

Sweep Angles effect: The larger the sweep angle, the stronger the vorticity magnitude is and longer it lasts.

For all Reynolds Numbers we have studied, at some point, the first pair of vorticity fields start to detach from the wall and a second pair of vorticity appears wrapping the first one.