Erosion Failure of Horizontal Pipe Reducing Wall in Power-Law Fluid Containing Particles via CFD-DEM Coupling Method.

A CFD-DEM-based two-phase flow model and a test-based erosion model are used to obtain the specific erosion on the reducing wall of sudden contraction section. The dimensionless filtered governing equations are adopted for incompressible power-law fluid flow, and the Hertz-Mindlin (no-slip) model for particle-particle and particle-wall contact. The annular reducing wall is divided into two erosion areas in radial direction based on erosion form and divided into four parts in the circumferential direction. The calculated result is verified with a full-scale experiment, and it shows a good agreement. The calculated results show that the erosion rate of the reducing wall is mainly determined by the flow velocity, and the erosion area is affected by liquid viscosity. The serious erosion region is located in the inner edge of the sample lower part, and this region expends to the outer circumference with the increasing flow velocity and the reducing liquid viscosity. The increase in flow velocity expands the flow region where the particle can impact the wall and thus increases the particle impact numbers. Graphical Abstract: [ABSTRACT FROM AUTHOR]