Author(s)

F. Ballio & S. Franzetti

Abstract

When a two-dimensional boundary layer on a plane surface encounters an obstacle, a three-dimensional separation is induced, and a complex necklace vortex system is created. In this paper, numerical solutions for the laminar vortex flow generated at a cylinder-wall intersection are analysed with respect to their topological structures. The nature and connections of singular points for the velocity and shear stress fields are identified. The topological consistency of the resulting vortex pattern is thoroughly discussed, as well as its robustness to changes in the physical and numerical parameters. Similar numerical and experimental results in the literature are considered for a comparison. Our analysis shows that both an insufficient spatial resolution and numerical or experimental errors may easily lead to misinterpretation of the vortex

Keywords