Steady flow patterns and interactions around vertical cylinders

초록

Vertical cylinders are commonly and widely used in offshore as dolphin structures. In a multiple array of vertical cylinders, flow patterns are very complex and interactive between cylinders. Generally, the patterns are turbulent and non-linear depending on various factors. The space and flow velocity of upstream can affect on the downstream body. In this study, the flow patterns around vertical cylinders are investigated by experiment with various spaces between cylinders and flow velocities. The interaction between cylinders is very important to understand the complex behavior of flow and to estimate the pressure field around the bodies. The pressure change is closely related to the estimation of hydrodynamic loads on the cylinders. The pressures around the flow field are measured at twelve holes. The experiment is conducted in a circulating water channel with visualization system. The laser beam is used to reflect the image from water particles for recording. The cylinders are spaced from 1D to 5D with various incoming flow velocities. From the study the consistent trends of pressure gradient around vertical cylinders are obtained. The results can be applied in the understanding and design of multiple pile array structures.