ABSTRACT
Submerged horizontal cylinders, sewage pipelines, water conveying pipelines, cable, etc., are placed on river beds. Flow separates when it passes over these structures with formation of a turbulent wake. The wake region contains numerous turbulent flow structures. The turbulent flow structures play prime role in the scouring of bed around the pipes. The wake region is ubiquitous in nature and it is very important to from view point of scouring phenomenon which decided the stability of the structures. Therefore, the key purpose of this research is to analyze the turbulent properties of the flow in the near-wake zone of a circular cylinder. For this purpose, experiments were conducted in a rectangular shaped flume made up of a rough bed. Three dimensional (3D) instantaneous velocity field was measured using an Acoustic Doppler Velocimetry (ADV). The raw velocity data were considered carefully and were processed before the analysis. The approach flow was found to be a boundary layer flow. In the near-wake zone of the cylinder, the increased turbulent properties like turbulence intensities, Reynolds shear stress (RSS), and turbulent kinetic energy (TKE) were observed. The present investigation will add to the insight into the field of the turbulent flow downstream of surface-mounted cylindrical objects positioned horizontally in rough bed natural streams.
