Effects of Three-Dimensional Imposed Disturbances on Bluff Body Near Wake Flows:Effects of Taper and Splitter Plates on the Near Wake Characteristics of a Circular Cylinder in Uniform and Shear Flow

摘要

The near wake characteristics of a circular cylinder were modified by use ofsplitter plates, cylinder taper, and shear flow to investigate the relationship between the various near wake parameters. The results are based on hot wire and mean pressure measurements, flow visualization of the near wake, and linear stability analysis of the shear layer. The straight cylinder variation in Strouhal number with respect to splitter plate length was divided into four regions identified by the flow phenomenon that dominates the shedding frequency selection namely, stabilizing, shear layer elongation, reduced entrainment, and splitter plate-vortex interaction. A sinuous plate increased the 2-dimensionality of the shear layer compared to the straight plate and affected the spanwise coherence of the Karman vortices. However, within the formation region the sinuous splitter plate produced results similar to those produced by a straight plate of equal average length. (AN).