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An accurate prediction of hydro-abrasive erosion helps in design, planning and operation strategies of a hydropower plant. In the empirical erosion model from the International Electrotechnical Commission (IEC) 62364 standard, various terms such as flow co-efficient (K f), material factor (K m) and exponent (p) were not provided for Pelton turbines components. The present paper aims to find the values of these terms and to interpret inadequately defined terms like erosion depth (S) and shape factor (K shape) for application of IEC 62364 (2013)# model. From some field and laboratory data, the values of K f and p were obtained for Pelton turbine components using multivariate regression analysis. The obtained values of K f are in the order of 10−6 and 10−12 for various zones of buckets and nozzle assembly respectively whereas p values are in range 1–5. The K m values for 6 different materials, i.e. three types of chrome nickel steels, plasma and high velocity oxygen fuel (HVOF) sprayed coatings and bronze buckets were obtained as 1, 1, 1, 0.6, 0.1 and 2.2, respectively. #IEC 62364 (2013). Hydraulic machines - Guide for dealing with hydro-abrasive erosion in Kaplan, Francis and Pelton turbines. Edition 1.0 (June 2013), International Electro technical Commission, Geneva, Switzerland. Image 1 • Unknown terms of IEC 62364 (2013) standard are found for Pelton turbine components. • Interpretation for inadequately defined terms of IEC 62364 (2013) is provided. • Material factor is found for 6 types of materials including two types of coating. • A sensitivity analysis revealed the effects of various parameters on IEC model. • Practical aspect of measurement with respect to IEC 62364 (2013) is also provided. [ABSTRACT FROM AUTHOR]

Abstract: Many correlations of mean hourly direct luminous efficacy for all sky, clear sky and intermediate sky conditions have been compared with experimental data measured in Arcavacata di Rende (Italy), Geneva (Switzerland), Vaulx-en-Velin (France), Bratislava (Slovakia) and Osaka (Japan). The comparisons show that, for all sky conditions, the correlations developed for one locality predict the luminous efficacy in the other localities with mean errors between −13% and 20% and root mean square errors between 15% and 35%; for clear sky conditions, the correlations developed for one locality predict the luminous efficacy in the other localities with mean errors between −7% and 14% and root mean square errors between 7% and 19%; for intermediate sky conditions, the correlations developed for one locality predict the luminous efficacy in the other localities with mean errors between −17% and 26% and root mean square errors between 20% and 41%. If the correlations with local coefficients are applied in each locality, the errors become considerably shorter. The paper gives indications on the values of the measured mean luminous efficacies and on the best models. [Copyright &y& Elsevier]