International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Pelton mini hydro-turbine, more concretely its turbine circle buckets was completely damaged during explotation conditions i.e. working time of about two years and half. Because turbine was ensured in ensured company, representatives of the company engaged court expert prof Cvetkovski to perform investigations (analysis) and to determine the reasons for these accidents. Normally working time of the Pelton turbine is about ten years, but there is examples that it can work even twenty years if construction and maintains of turbine was properly done. Therefore, the purpose of the conducted expert examination is to analyze the causes, effects and potential solutions for the damaged Pelton turbine. This report covers the technical aspects, the mechanisms that contribute to the appearance of defects, that is, damage of the buckets of the Pelton turbine. In order to find the reason of failure of the turbine buckets, as first complete visual inspection of the turbine wheel was performed. As additional investigation was performed chemical analysis of the buckets, measuring of its hardness and metallographic investigation (determination of type and quantity of non-metallic inclusion and microstructure).

In this study, series of CFD simulation were carried out for two phase flow (free surface), three dimensional geometry and turbulent flow through the pelton turbine. The present investigation employed on the pelton turbine bucket models various splitter angle and inlet velocity values for visualizing the flow pattern and identifying the force on the bucket. In this study, Two different bucket models were applied at different inlet velocity (20, 25, 30,35and 40m/s) and four different splitter angle (55, 75,90and 115) for finding the effect of every single parameter on the effective force on the bucket. The obtained results discovered that there is a linear relationship between force and inlet velocity on the bucket. It uncovered that relationship between splitter angle and force on the bucket is linear until 90 degree after that this relationship is a non-linear.