Transient Hydraulic Transport in Pipelines

Abstract

Hydraulic transport pipelines are used in dredging, (wet) mining and deep sea mining. These pump-pipeline systems are typically designed using steady-state principles. However, recent cases have shown that steady-state design does not always guarantee stable pipelines. Transients like self-amplifying density waves have shown to be able to destabilize pump-pipeline systems, increasing the risk of blockages and/or pump-drive failures. In this dissertation, these unstable transients were studied, and the mechanisms behind three density wave types were unraveled. Furthermore, this work aimed at developing new transient modelling techniques using 1D-Driftflux-CFD, which can predict density wave amplification. This 1D-Driftflux model was used to study new design methods, such as strategically lowering the pipe diameter in certain sections of a pipeline, and applying flow feed-back control. These new insights also open the way towards making long distance pipelines more efficient, such that they can transport sediment at higher concentration and/or lower flow velocities.