Author(s): Raul-Alexandru Szakal; Alin-Ilie Bosioc; Constantin Tanasa

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Keywords: No Keywords

Abstract: Off-design conditions, particularly part-load operation, are problematic for hydraulic turbines with fixed blades, causing issues like vortex rope formation in the draft tube, which reduces turbine efficiency and causes vibrations and damage. The classical axial water jet injection (14%) is an effective active flow control method used to control vortex rope. This paper explores developing a new active flow control method using a radial-axial water jet with a lower flow rate than the classical method. A regulation valve is introduced. Experimental work analysed unsteady pressure fields in the draft tube cone, focusing on pressure pulsation spectra at four levels and the effect of valve openings and flow rates. A radial-axial injection below 6% of the main flow reduced flow unsteadiness significantly.

DOI: https://doi.org/10.1088/1755-1315/1561/1/012036

Year: 2025