Determination of the Drag Reduction Mechanism Associated with the Pneumatic Regulation of Slurry Pipeline Transport using a Numerical Method

The technological parameters associated with the pneumatic regulation of slurry pipeline transport have been explored to reduce the energy consumption of the transport system and prolong the transport distance in dredging cases. In this study, a numerical method is employed to discretize and solve the established three-dimensional physical model, which consists of a dual Eulerian model of multiphase flow, the standard k-epsilon model of turbulence, and a homogeneous flow model for slurry. The simulated pressure drop values are consistent with the experimental results for transport with gas injection. In addition, the influence of the gas phase on the flow characteristics in the pipeline is analyzed, and the mechanism of the drag reduction is revealed. The presence of the gas film reduces the wall shear stress between the slurry and the pipe wall, which is the root cause of the drag reduction. Under the control of pneumatic regulation, the flow state tends to stabilize in the fully developed section of the pipe, and injection does not interfere with transport.