Effect of Permeability and Length of a Perforated Splitter Plate Downstream of the Circular Cylinder

Abstract

Extensive research has been conducted on the flow control of bluff bodies to address negative impacts such as vibration, acoustic noise, and resonance caused by wake flow. The circular cylinder, due to its simple geometry, is frequently studied as a bluff body and is utilized in various engineering applications including cooling system pipes, electrical pylons, industrial flue systems, overpasses, satellite antennas, electrical cables, and marine drilling platforms. In this investigation, a perforated splitter plate was strategically positioned at different downstream locations to manage the wake flow of the cylinder. The experiments were conducted in a sophisticated, closed-loop water channel at the Fluid Mechanics Laboratory of Cukurova University, providing a controlled environment for precise flow analysis. To measure the instantaneous velocity vector field in the wake region of the cylinder at a Reynolds number (Re) of 5000 (based on the cylinder diameter, D), particle image velocimetry (PIV) was employed. Three different permeability values for the splitter plate (e=0.30, 0.50, 0.70) and three lengths (ls*=1, ls*=2, ls*=3) were tested, maintaining a constant gap (G/D=1) between the splitter plate's leading edge and the cylinder surface. The splitter plates were aligned with the flow direction (ϴ=0°). The permeable separator plates minimize the interaction of boundary layers formed around the cylinder, enhancing their effect in downstream regions where shear layer interaction is more pronounced. Consequently, this results in reduced fluctuations and a more stabilized wake flow downstream of the cylinder.

Keywords

• cylinder
• flow control
• perforated splitter plate
• piv