Improved CFD modeling and validation of erosion damage due to fine sand particles

Using an Eulerian-Lagrangian approach, numerical erosion modeling of a 90° sharp bend in water-sand slurry flow is performed. The numerical results are validated with experimental data in the literature [1]. Two different sand types, 25 µm sharp silica sand and 256 µm rounded quartz are used. The carrier fluid velocity is varied from 15.2 m/s to 26.2 m/s. The total mass loss and local wall thickness loss in upstream and downstream sections of the sharp bend are calculated and compared with experimental data. Two models are employed for resolving the near wall region, standard wall-function and low-Re number approach. It is found that for large particles (256 μm) the erosion results predicted by both models agree well with experimental data. However, using the standard wall function for small particles (25 μm) produces non-physical particle trajectory near the wall. This leads to over prediction of experimental data by about one order of magnitude. The numerical results show that adequately resolving the near wall region and employing the low-Re number model can significantly improve the erosion prediction resulting from small particles.