Pelton turbines operate by converting the kinetic energy of water jets into mechanical torque through impulse-driven action. In this talk, we will present a meshfree framework based on the Generalized Finite Difference Method (GFDM) to model the multiphase flow inside a Pelton turbine. The model captures the interaction between air, water, and sediment particles (primarily sand), with each phase represented by a meshfree/particle-based approach. This three-phase coupling allows us to investigate the hydrodynamic performance and blade erosion mechanisms in a unified framework. Our presentation will cover: (i) the generation and impact of high-velocity water jets from the nozzle, including accurate tracking of the free-surface and nozzle filling process, (ii) the three-phase air-water-sand coupling, (iii) the abrasive wear caused by the sand particles on turbine buckets. We also analyse the torque on different parts of the geometry to identify performance bottlenecks and efficiency losses. Our modelling framework will be validated against experiments from our industrial partner. The proposed modelling approach aims to support modernization efforts of existing hydropower plants by enabling more accurate predictive simulations. The use of a meshfree method allows handling complex and moving geometries, an ease of handling free surfaces, and efficient coupling across the different phases in a single computational framework.