Flow Analysis Inside a Pelton Turbine Bucket

Abstract

The aim of this work is to provide a detailed experimental and numerical analysis of the flow in a fixed bucket of a Pelton turbine. The head, jet incidence, and flow rate have been varied to cover a wide range of the turbine functioning points. The experimental analysis provides measurements of pressure and torque as well as flow visualization. The numerical analysis is performed with the FLUENT code using the two-phase flow volume of fluid method. The results present a good consistency with experimental data. In particular, the pressure distribution is very well predicted for the whole range of the studied parameters. A detailed analysis of torque and thrust allows evaluating the losses due to the edge and the cutout of the bucket. These results give insight into the benefit we can expect of steady flow calculations through the optimization process of the design of Pelton turbines.

Development of hydro impulse turbines and new opportunities

“…A study using Fluent on the stationary bucket case was performed where the chosen multiphase model was VOF and the turbulence model was k-ε [61]. Excellent agreement to the experimental results was reported at most locations except at the cutout.…”

“…There is a study [67] that used an Inhomogeneous multiphase model with k-ω SST in CFX-11 despite the publications reporting slightly higher computation demands of the Inhomogeneous model [29,61,68]. The importance of modelling a real jet was highlighted and a disagreement 6% between the numerical and experimental results was claimed.…”

State of the art in numerical modelling of Pelton turbines

“…The chosen turbulence model was the k-ω SST. After the initial comparison of homogeneous and inhomogeneous models for multi-phase flow the Inhomogeneous model was chosen despite the slightly higher computation demands and publications of Janetzky et al [45], Kvicinsky [34] and Zoppé et al [52] highlighting a satisfactorily agreement between numerical and experimental results with Homogeneous model. The decision was justified by the fact that Inhomogeneous model showed higher stability.…”

“…Results of modelling the flow inside a stationary bucket performed with Fluent were published by Zoppé et al [52]. The VOF multiphase model was used for simulating the free surface and the k-ε model was used for turbulence.…”

Numerical Investigation of the Spear Valve Configuration on the Performance of Pelton and Turgo Turbine Injectors and Runners

“…The Homogeneous multiphase method was selected in ANSYS® CFX® based on the available published research in this area [26][27][28][29][30]. The high resolution advection scheme was chosen which uses a Fourth Order numerical model and blends to Second Order near pressure extrema as used in [23].…”