Numerical exploration of flow topology and vortex stability in a curved duct
Resource
International Journal for Numerical Methods in Engineering,71,564-582.
Journal
International Journal for Numerical Methods in Engineering
Pages
564-582
Date Issued
2007
Date
2007
Author(s)
Sheu, Tony W. H.
Tsai, S. F.
Abstract
Abstract We performed incompressible flow simulation in a square duct with 90° bend and a curvature radius of 2.3 to extend our understanding of the vortical flow development in the bend. The solutions for the flow investigated at the Reynolds number of Re =790 are obtained in a tri‐quadratic element system, where velocities stagger the pressure working variable, using the streamline‐upwind finite element model and the BiCGSTAB iterative solver. The simulated results reveal that centrifugal force convects the quickly moving fluid particles towards the outer wall. The axial velocity, as a result, shows twin peaks in the curved channel. At about θ=66°, the secondary flow shows three complex pairs of vortices. Also noteworthy is the formation of a downstream spiralling flow motion. To better elucidate the dominating three‐dimensional flow nature, the topological study of limiting streamlines was undertaken. Insight into the longitudinal flow instability is gained by tracking the formation and diminishing of limiting cycles. Copyright © 2006 John Wiley & Sons, Ltd.
SDGs
Type
journal article