Erosion Estimation on the Impeller Blades of Centrifugal Dredge Pumps
Type:
Presented during:
WODCON XXIII - Dredging is changing - The Practice. The Science. The Business.
Authors:
S. Sapkota, W. Kleermaker, R.A.W.M. Henkes, A.H. van Zuijlen
Abstract
"The focus of the project is on developing, validating, and demonstrating a numerical model capable of estimating the erosion wear due to slurry flow on the impeller blades of a centrifugal dredge pump by using Computational Fluid Dynamics (CFD). The numerical computations are performed using the commercial software ANSYS Fluent with the Eulerian Lagrangian framework for the mixture of water and sand particles. For the turbulence of the water, the k-ω SST turbulence model is used. The collisions of the particles with the wall are modeled using the Grant-Tabakoff model, whereas the linear soft sphere model is used for the inter-particle collisions. Oka model is used for erosion modelling. A benchmark study of submerged impinging jet and the numerical computation with impeller was performed as part of the numerical study and compared with the experimental results from the literature review. From the impinging jet benchmark, it is found that the fluid and particle velocity fields can be calculated with reasonable accuracy. It appeared that there is a considerable dependency of the erosion profile on the material hardness. By comparing the resulting erosion profile from the two-way coupled model with the experimental erosion, a reasonable qualitative and quantitative agreement is found. A numerical and experimental investigation has been conducted on the erosion of impeller blades close to the Best Efficiency conditions to predict the extent of the erosion wear concerning the velocity flow field, particle trajectories, and other factors such as particle diameter, and grid size. Experiments were conducted in a facility that is available within the company Damen Dredging Equipment. For the quantification of the erosion wear, a Coordinate Measurement Machine (CMM) is used. By measuring several points on the impeller blade surface before and after a 55.7-hour experiment, the resulting erosion could be determined. The two-way coupled numerical model showed good correspondence with the experimental results. "
Keywords: sediment erosion, centrifugal pumps, CFD, ANSYS, coordinate measurement machine