Experimental Study on Flow Characteristics Around a Submerged Half-Buried Pipeline

Abstract

This paper describes the flow characteristics around a half-buried pipeline exposed to different current conditions by flume experiment. Particle Imaging Velocimetry (PIV) technique was used in the experiment to reveal the flow structure. The experiment results indicate that the hydrodynamic parameters, including average kinetic energy, vorticities, Reynolds shear stress, and kinetic turbulence energy, increased with the Renolds numbers. Furthermore, it is found that the vortex at the upstream side of the half-buried pipeline vanishes gradually with increasing Renolds numbers. However, the two vortices at the locations downstream of the half-buried pipeline exist all the time, in which the vortex closed to the downstream of the pipeline becomes unstable, the vortex at the pipeline wake remains unchanged. In the meantime, the turbulence intensity at the upstream side of the half-buried pipe near the bed surface strengthens significantly under Reynolds number conditions, which may accelerate the potential scour process in front of the pipeline.