Summary: Coherent Structures in a Transitional Flow
around a Backward-Facing Step
Submitted by
Tino Weinkauf and Hans-Christian Hege, Zuse Institute
Berlin (ZIB)
Bernd R. Noack, Michael Schlegel, and Andreas
Dillmann, Technical University Berlin
The transitional flow around a backward-facing step is
visualized using illuminated streamlines of a snapshot Fig.
1 . The flow separates at the corner of the step. The resulting
shear layer rolls up in two Kelvin­Helmholtz vortices. In the
downstream direction, the streamlines form bundles due to
secondary streamwise vorticity. The fluid experiences a small
backward flow in the upstream region below the shear layer.
The flow field is obtained from a large-eddy simulation by
Kaltenbach and Janke at a Reynolds number of ReH 3000
based on oncoming velocity and on step height. The corre-
sponding boundary conditions are described in Ref. 1.
The streamlines are illuminated in order to enhance the
three-dimensional perception of the scene. This highly inter-

Source: Andrzejak, Artur - Konrad-Zuse-Zentrum für Informationstechnik Berlin
Noack, Bernd R. - Département Fluides, Thermique, Combustion, Université de Poitiers

Collections: Computer Technologies and Information Sciences; Engineering