Particle image velocimetry evaluation of flow-altering countermeasures for local scour around a submerged circular cylinder

• 作者: Priscilla Williams Ram Balachandar Vesselina Roussinova Ronald Barron
• 来源期刊: 国际泥沙研究（英文版）
• 年，卷（期）: 2022,（4）
• 页码范围: 411-423
• 页数: 13页
• 语种: 英文

摘要

The effect of scour countermeasures on the mechanism of local scour around a cylinder requires clari-fication in order to develop design methodology for use in practice.Previous investigations on coun-termeasure performance,though useful,have not provided adequate measurements to support this understanding.In the present investigation,particle image velocimetry(PIV)measurements were ac-quired at several streamwise-vertical planes in the flow field surrounding a submerged circular cylinder with a vertical splitter plate and with a rectangular collar(a horizontal base plate).Analysis of the distribution of mean streamwise velocity and Reynolds shear stress as well as the scour formation indicated that the splitter plate disrupted shear layer interaction in the wake region,reducing the width of scour downstream of the cylinder by 3％.The collar eliminated scour upstream of the cylinder entirely by providing protection at the sides of the cylinder where the shear stress exceeds the critical bed shear stress,and the streamwise velocity distribution in the region between the cylinder and the channel sidewall indicated that installation of a rectangular collar causes flow separation at a point further up-stream on the cylinder surface.