Characterization of the hydrodynamics within a toroid wear tester

Abstract

AbstractThe toroid wear tester (TWT) is a lab‐scale device used for the assessment of slurry erosion in pipelines. Historically, its application has been limited to the relative ranking of material performance under different slurry flow conditions; however, recent studies have indicated that TWT tests could be predictive and directly applied to slurry pipeline design—provided that the flow inside a TWT is better characterized. In the present study, air‐liquid multiphase flow inside the TWT was investigated. Torque measurements were taken to characterize friction loss for different air‐liquid combinations. A visualization experiment was also conducted to evaluate flow patterns within the TWT. In the experiment, the displacements of spherical glass beads were used to estimate velocity vector fields for different TWT rotational speeds. A computational fluid dynamics (CFD) analysis was also conducted to complement the experimental measurements. A 3D transient analysis using the volume of fluid (VOF) approach was used to model the system. The simulation results agreed closely with the experimental findings. Furthermore, the simulations revealed that strong secondary flows (back flow, rotation) exist in the TWT. These type of flows do not occur in horizontal pipelines. Therefore, to use the TWT as a tool for slurry pipeline wear assessment, the differences in the flow field between the two systems must be properly quantified.