Interference Between a Square and a Circular Cylinder

Abstract

The flow visualization studies around a square cylinder (upstream) and a circular cylinder arranged in tandem configuration is studied experimentally to identify the interference flow patterns. Flow visualization studies are carried out in a re-circulating water channel. The investigations are carried out for tandem arrangement varying the center-to-center distance (L) between the cylinders; L/B ratio is varied from 1 to 5 where B is the characteristic length. Experiments were conduct at a Reynolds number of 2100 (based on B). The results are also obtained for two tandem square cylinder configuration. The flow patterns observed are: Alternate Shear Layer Reattachment with and without gap flow, Simultanous shear layer reattachment and detached shear layer flow pattern. The time of persistence (in percentage) for each flow pattern is estimated over a sufficiently long period of observation time to identify the most influential, predominant flow pattern. Though these patterns are identical for square-square and square-circular tandem configurations, their order of predominance is different for both the configurations.