Author(s): O Kirschner; C Geiger; S Riedelbauch

Linked Author(s):

Keywords: Cavitation localization; Beamforming; Acoustic emission sensors; Cavitation channel

Abstract: Cavitation typically occurs in hydraulic turbines operating in off-design conditions. Since direct investigation on prototype machines is very difficult, one approach is to measure the bubble collapse noise to localise the cavitation zone. To significantly reduce the complexity of the problem, this paper presents the results of a basic experiment on localizing cavitation using beamforming in a cavitation channel. Therefore, an array of acoustic emission sensors is installed on the top of a face-milled steel cover of a cavitation channel. The acoustic emission of a cavitating hydrofoil is captured by the acoustic emission sensors. Beamforming algorithms are used to determine the position of the cavitation by evaluating acoustic sensor signals. In addition, optical accessibility is ensured by an acrylic glass window. This allows the visual inspection of the cavitation positions determined via beamforming. The results of the investigation show that the method can be used to identify the location of the area with bubble collapse in the cavitation channel.

DOI: https://doi.org/10.1088/1755-1315/1483/1/012006

Year: 2023