F. Rehimi - Université de Monastir, École Nationale d’Ingénieurs de Monastir, Laboratoire LESTE, Avenue Ibn El Jazzar ۵۰۱۹ - Monastir, Tunisie
F. Aloui - Université de Nantes, Faculté des Sciences et des Techniques, Département de Physique, ۲, rue de la Houssinière BP ۹۲۲۰۶ - ۴۴۳۲۲ Nantes Cedex ۰۳, France
S. B. Nasrallah - Université de Monastir, École Nationale d’Ingénieurs de Monastir, Laboratoire LESTE, Avenue Ibn El Jazzar ۵۰۱۹ - Monastir, Tunisie

Experiments were performed at low Reynolds numbers in the range ۷۵ Re ۲۷۵ in the wake of a circular cylinder of dc diameter placed symmetrically between two parallel walls of H height. ۲D۲C particle image velocimetry (PIV) was used to investigate the flow downstream the cylinder. In the unsteady flow regime downstream the cylinder, the detached primary vortices (Pi) interact with walls generating secondary ones (Pi’) and modify the cylinder wake dynamic. The kinematical properties (advection velocity, circulation, rotation kinetic energy, etc.) of the generated secondary vortices are studied and compared with the primary ones in order to show how the walls influence the von Kármán vortex street. The authors propose here a relation between the circulations and kinetic energies of primary and secondary vortices.

Confined cylinder wake, ۲ criterion, PIV measurements, Von Kármán vortices, Coherent structures, Wall, Vortex interaction