Experimental study of cavitation erosion around a surface-mounted semi-circular cylinder
Paper in proceedings, 2019

The objective of this study is to investigate the collapsing behavior of cavitation, which leads to erosion. For this purpose, an experimental investigation was performed in a channel with a semi-circular cylinder obstacle at the Hydraulic Laboratory of ANDRITZ HYDRO in Vevey. Cavitation was achieved by employing a range of pressure differences over the test section. The obstacle promotes and localizes cavitation-induced erosion. The flow field behind the semi-circular cylinder was investigated as a characteristic example of bluff bodies, which exhibit a distinct separated vortex flow in their wake. A high-speed camera observed the cavitation behavior. At the same time, erosion tests were performed using paint (stencil ink). The intensity of cavitation is described by the cavitation number (σ), the lower the cavitation number, the higher the cavitation intensity. Three erosive cases at different cavitation numbers are presented here. The erosion (removal of paint) after 40-60 mins of operation revealed distinct and repeatable results. These results will serve as validation data for numerical studies. For a high cavitation number, a large number of Karman-vortex-like cavities are shed downstream of the obstacle. This results in a higher number of collapse events and ultimately more erosion. On the other hand, at lower cavitation numbers the erosion took place at the closure line of the cavity. We demonstrate that paint tests in combination with this geometry provide an efficient and economical way to investigate erosion patterns compared to expensive material loss tests.

semi-circular cylinder

cavitation erosion

vortex shedding

Author

Saad Jahangir

Delft University of Technology

Ebrahim Ghahramani

Chalmers, Mechanics and Maritime Sciences, Marine Technology

Magdalena Neuhauser

Andritz Hydro

Sébastien Bourgeois

Andritz Hydro

Rickard Bensow

Chalmers, Mechanics and Maritime Sciences, Marine Technology

Christian Poelma

Delft University of Technology

10thInternational Conference on Multiphase Flow, ICMF 2019
Rio de Janeiro, Brazil,

Development and experimental validation of computational models for cavitating flows, surface erosion damage and material loss (CaFE)

European Commission (Horizon 2020), 2015-01-01 -- 2019-01-01.

Areas of Advance

Transport

Subject Categories

Applied Mechanics

Fluid Mechanics and Acoustics

Infrastructure

C3SE (Chalmers Centre for Computational Science and Engineering)

More information

Latest update

6/10/2019