Projeto e análise Vof transiente de rotores Pelton

Abstract

This work presents a methodology for the conceptual design of Pelton turbines, where configurations or dimensions are determined as a function of the nominal load condition. To determine the energy and hydraulic efficiency of the turbine, losses in terms of specific energy are introduced, and leakage and mechanical losses are then considered. This methodology allows obtaining the spatial coordinates that represent the concave surface of the bucket. The preliminary results of the project are compared with a numerical model in transient regime (CFD), procedures and methodologies for the simulation are presented in details, such as the construction of the mesh in the non-inertial domain, represented by five buckets and sliding mixing interfaces between the inertial and non-inertial domains. The multiphase, VOF and turbulence k-ω / SST models were selected considering step time values around 0.000185 s., in order to represent the instantaneous torque resulting from the interaction between the buckets and the jet. Simulation results were extended to analysis of hydraulic efficiency, at the design point and at part load.