Experimental Characterization of Hydraulic Solid Particle Transportation in Horizontal Pipelines Using PIV

Solid particle transport in pipelines by fluids is encountered in a wide variety of industry processes, such as oil production, mining and chemical industry. In contrast to the intensive research effort that has investigated transport modes for suspended solid particles in pipeline flow, limited studies have been published on solid transportation mechanism generated from an initial stationary particle bed. Consequently the underlying mechanisms responsible for bed-load and saltation transport phenomena have not been extensively assessed, particularly for low velocity hydraulic conveying pipe flows. This paper presents an experimental investigation into sand particle transportation from a stationary horizontal particle bed under hydraulic conveying flow for bed-load and saltation transport phenomena. Experiments were undertaken in a laboratory environment using a 14 m long transparent plexiglas loop of 24 mm internal diameter to permit optical access. High speed digital photography was employed to study the morphologic characteristics of sand bed transportation, with Particle Image Velocimetry (PIV) used to characterize the near surface flow structure at the fluid-solid interface. Experimental results characterize the influence of water flow on sand dune formation for one bed thickness and particle size. Flow field velocity distributions revealed the presence of vortex structures that strongly influence the dynamics of sand dunes. The results presented on the combined study of flow field and bed formation interaction provide a fundamental insight into the physics of fluid-solid interaction in a closed conduit that can also serve as benchmark data for computational fluid dynamics based predictions.