The interference effect of a wall on the flow around two circular cylinders

The interference effect of a wall on the flow aroundtwo circular cylinders arranged in tandem was experimentallyinvestigated in the subcritical range of Reynolds numbers.The cylinders spanned the test section of a wind tunnel andwere aligned with their axes parallel to the plate and normalto the free stream. The upstream cylinder was placed 13diameters downstream of the leading edge of the plate. Thedownstream cylinder was located at the required spacing lidwhich ranged from 1.0 to 6.0 (where I denotes the distancebetween the two centers of the cylinders and d is thecylinders and the wall hid was varied from 0.0 to 4.0 (whereh denotes the gap between the cylinders and the wall). Thediameter of the cylinder). The distancebetween the experiments were carried out in the subcritical rangeat a Reynolds number based on the cylinder diameter, of•3.8 x 10 . The study describes the effect of the wall on thepressure distribution and forces actingon the two cylinders. Also the effect of the wall on the bistable flowat the critical spacing and on the flow in the wake of thecylinders is investigated. Changes of the flow pattern alongthe wall during the various phases of the interference withthe cylinders were measured.