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oai:recercat.cat:2117/3747362026-02-04T07:41:20Zcom_2072_1033col_2072_452950

Determination of the natural frequencies of a prototype Kaplan turbine Valero Ferrando, Ma. del Carmen Egusquiza Montagut, Mònica Valentín Ruiz, David Presas Batlló, Alexandre Moraga González, Greco Alonso Universitat Politècnica de Catalunya. Departament de Mecànica de Fluids Universitat Politècnica de Catalunya. Doctorat en Enginyeria Mecànica, Fluids i Aeronàutica Universitat Politècnica de Catalunya. CDIF - Centre de Diagnòstic Industrial i Fluidodinàmica Àrees temàtiques de la UPC::Enginyeria mecànica::Mecànica de fluids::Màquines hidràuliques i de fluids Hydraulic turbines Kaplan turbines Mode shapes Natural frequencies Resonance Turbines hidràuliques The natural frequencies of a turbine can be calculated from numerical methods. By comparing these natural frequencies with excitation sources, one can know the danger of a resonance and a possible failure in a component of the turbine. Therefore, it is often very important to have an accurate numerical model of the turbine to determine these natural frequencies. There are not many publications on the determination of the natural frequencies of reduced-scale models of Kaplan turbines. More papers exist for pump turbines or Francis turbines. For real Kaplan turbines, very few experiments can be found to determine mode shapes and natural frequencies. In this paper a Kaplan turbine of 37MW (maximum power), 12.5m (maximum head) and 50 m3 /s (maximum flowrate) was tested. The turbine was equipped to determine the natural frequencies of the runner in air. For this purpose, one accelerometer in each blade of the runner was installed and a total of 16 impacts were done in each blade. Frequencies and mode shapes were obtained. In parallel, a numerical model was obtained. Numerical and experimental results were compared and an accurate numerical model is presented. With this numerical model the natural frequencies of the runner in water were calculated. This research activity is framed within the context of the XFLEX HYDRO project. The project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 857832. No. 857832). Peer Reviewed Postprint (published version) 2022-09-01 Article Valero, M. [et al.]. Determination of the natural frequencies of a prototype Kaplan turbine. "IOP conference series: earth and environment", 1 Setembre 2022, vol. 1079, núm. Article 012022. 1755-1307 https://hdl.handle.net/2117/374736 10.1088/1755-1315/1079/1/012022 eng https://iopscience.iop.org/article/10.1088/1755-1315/1079/1/012022/pdf info:eu-repo/grantAgreement/EC/H2020/857832/EU/Hydropower Extending Power System Flexibility/XFLEX HYDRO https://creativecommons.org/licenses/by/3.0/ Open Access Attribution 3.0 Unported application/pdf Institute of Physics (IOP)