On the Flow Characteristics around a Circular Cylinder according as the Water Depth from the Free Surface

Gim, Ok-Sok; Shon, Chang-Bae; Lee, Gyoung-Woo

Journal of Navigation and Port Research 2010;34(5):331-336.
Published online June 30, 2010.

자유수면에 인접한 원형실린더형 몰수체 주위의 유동특성에 관한 연구

김옥석, 손창배, 이경우

On the Flow Characteristics around a Circular Cylinder according as the Water Depth from the Free Surface

Ok-Sok Gim, Chang-Bae Shon, Gyoung-Woo Lee

Abstract

The free surface influenced the wake behind a circular cylinder and its effects were investigated experimentally in a circulating water channel with the variation of water depth. Instantaneous velocity fields were measured in this paper. The measured results has been compared with each other to investigate the flow characteristics of the circular cylinder's 2-dimensional section at Re=1.0×10³using 2-frame grey level cross correlation PIV method. The flow around the circular cylinder with free surface affected the wake structure. Especially, in case of d=1.0D, the boundary layer was measured in the whole area. The separation point and boundary layer of the circular cylinder could be controlled by the water depth.

Key Words: Circular cylinder;Flow field;Free surface;Particle Image Velocimetry