ANALYSIS OF PELTON BUCKET EFFICIENCY

This paper presents a method for the investigation of a Pelton bucket efficiency based on the analysis of the particles flow tracks. The fluid particles trajectories on the rotating bucket were determined integrating the results obtained by the unsteady numerical analyses carried out on the jet-bucket interaction. The computation was performed using a transient multi-phase homogeneous model and the jet was supposed to have constant diameter and axial-symmetric velocity profile. The numerical results were integrated by means of a predictor-corrector system, which combined two linear multi-step methods: a forth-order Adams-Bashford method as predictor and a fifth-order Adams-Multon method as corrector. The analysis of the fluid particle trajectories in the bucket together and of the single-particle momentum variation during the jet-bucket interaction allowed to examine the influence of the bucket geometry on the energy exchange of the turbine. The lagrangian approach of the proposed method also allowed to consider the losses associated with the leakage flow rate through the intake in the evaluation of the bucket efficiency.