Hydro-Abrasive Erosion in Pelton Turbine CFD Simulation Tutorial

Description

Introduction

Pelton wheel erosion is a significant concern in hydropower systems. The Pelton wheel, a key component of hydro turbines, is subjected to high-velocity water jets that can cause erosion over time. This erosion occurs primarily due to the impact of water droplets and sand particles on the wheel’s buckets or blades.

The material gradually wears away as the water repeatedly strikes the surface, reducing efficiency and potential damage. Various measures are employed to mitigate erosion, including using erosion-resistant materials, regular maintenance, and monitoring. Additionally, optimizing water flow and ensuring proper alignment can minimize erosion and extend the lifespan of Pelton wheels, ensuring efficient and sustainable hydropower generation.

The geometry used in this simulation is created with Design Modeler software, and the mesh grid is generated with ANSYS Meshing as an unstructured grid that contains 6,433,121 tetrahedral elements.

Hydro-Abrasive Erosion in Pelton Turbine Methodology

To investigate the hydro-abrasive effect, the simulation is performed with different water jet speeds, and the average erosion that occurs on the blades of the Pelton turbine is measured.

The turbulence model is set as K-Omega SST, and the multiphase VOF model simulates a water jet. The DPM model also enables to model of erosion as a 2-way DPM; the Pelton wheel motion itself is modeled using a Mesh Motion Approach.

Conclusion

After the simulation was performed, the results showed the direct impact of the high-velocity water jet on the Pelton turbine blades. create an erosion. The hydro-abrasive phenomena also depend on the varying water jet velocity. The as the velocity doubles.

The average erosion rate increases by 12%, which must be considered in the casting material process. The high erosion rate of the sand particles is a crucial factor in Pelton turbine design life expectancy.