Elektrane (2025) [pp. 235-241]
AUTHOR(S) / AUTOR(I): Aleksandar Stepanović, Ivan Božić, Bogdan Ristić, Ivana Vasović Maksimović
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DOI: https://doi.org/10.46793/EEP25.235S
ABSTRACT / SAŽETAK:
Reliable and stable operations of hydropower units are among the main priorities in the functioning of hydropower plants in extremely dynamic and demanding contemporary electric power systems. Everything that causes deviation from the stated priorities needs to be properly analyzed and, if possible, eliminated. Pressure pulsations that appear in a hydraulic turbine can have an impact on an increase in hydraulic oscillations and mechanical vibrations, structural damage, instability of the power transmitted to the generator, and resonance, as well as on a decrease in the efficiency of the hydropower unit. Numerous phenomena that occur during the exchange of energy in the hydraulic turbine flow domain cause pressure pulsations. Understanding fluid flow dynamics around an isolated hydro profile is the first and essential stage for optimizing the performance and the design of all types of hydraulic turbines. This paper provides an additional contribution to the unsteady water flow numerical analysis of the isolated NACA0009 hydro profile, truncated to 90% of its original length, in order to check and confirm the induced pressure pulsations. The simulations were conducted for different attack angles of the profile under constant outlet pressure and inlet flow velocity. Some of the numerical results were verified by the available experimental data and compared with other published results.
KEYWORDS / KLJUČNE REČI:
Unsteady Numerical Simulations, NACA0009 Hydro Profile, Pressure Pulsations, Pressure Coefficient
ACKNOWLEDGEMENT / PROJEKAT:
This research has been supported by the research grants No. 451-03-136/2025-03/200066 and No. 451-03-137/2025-03/200105 of the Ministry of Science, Technological Development, and Innovation of the Republic of Serbia.
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