Analysis of Transport Characteristics of Corrugated Acceleration Structure in Slurry Shield Discharge Pipeline

In response to the blockage situation in the discharge pipeline of the slurry circulation system in the slurry shield machine, a two-way coupling method based on Computational Fluid Dynamics (CFD) and Discrete Element Method (DEM) is used to simulate the transportation process of slurry and stone particles interacting in corrugated pipelines. The evolution of the particulate phase and the fluid phase over time was studied. The results show that: The corrugated pipeline achieves an accelerated effect on the converging pipe flow field with inward corrugations. The flow velocity of the slurry significantly increases when passing through the corrugated structure, and the high-speed flow area expands. More stone particles at the bottom of the pipeline change from sliding friction with the pipe wall to rolling friction, reducing the frictional wear between the stones and the pipeline, and the slurry at the bottom tends to flow upwards, giving the stone particles an upward velocity component, distributing them in a position with stronger flow field effects. Near the corrugated pipe wall, the turbulent kinetic energy increases with the flow of the slurry, while the friction loss between the slurry and the pipe wall and the thermal energy dissipation caused by the turbulent flow significantly reduce the total pressure. Increasing the amplitude of the corrugated function or decreasing the period is beneficial in alleviating the blockage of stone particles, but an excessively small period can cause individual stone particles to be retained for extended periods. Using a corrugated acceleration structure in pipe sections where stone particles tend to accumulate can effectively prevent clogging.