EXPERIMENTAL STUDY OF COHERENT FLOW STRUCTURES BEHIND TWO SIMILAR NORMAL FLAT PLATES IN TANDEM ARRANGEMENT

摘要

Flow structures behind two identical normal flat plates in tandem arrangement have been investigated for various gap ratios (g/D ) between the plates at a high Reynolds number of 3.3 × 10~(4). Constant-temperature hot wire anemometers (CTA) were employed to quantitatively measure the near wake properties behind the downstream plate. The effects of various gap ratios (g/D ) ranging from 0.2 to 2.0 were probed, and it was observed that the wake region behind the normal flat plates in tandem arrangement exhibits higher Strouhal number than a normal single flat plate. Moreover, the plotted contours demonstrated that the centerline behind the plates encountered a shedding frequency corresponding to twice the reference shedding frequency (2f_(s) ). Finally, regions associated with the highest Reynolds stress were spotted along the edges of the plates in the wake region.