A simple model of assessment of collapse aggressiveness of cavitation bubbles suitable for application at pump design stage is proposed. The model is focused on quantifying the energetic effects of single bubble collapses and the emphasis is placed on computational efficiency. The objective of the model is to provide a rapid estimation of the erosion risk for steady-state or near-steady-state flow with traveling bubble cavitation. The proprietary 3-dimensional Navier-Stokes code for turbulent flow in hydrodynamic machinery is coupled with the unreduced Rayleigh-Plesset equation for incompressible liquid by virtue of the iterations of continuity and momentum equations to account for density changes in the bubbly regions (two-way coupling). The model of collapse aggressiveness of the cavitation bubbles is based on the estimation of the energy dissipated between two successive bubble rebounds. The model is tested for a 2-dimensional hydrofoil in the cavitation tunnel of SIGMA Research and Development Institute in Lutin. The closed-loop tunnel is equipped with the acoustic bubble spectrometer to measure the nuclei population in the test section inlet. The erosion pattern of the hydrofoil surface is monitored using optical profilometry. The results indicate the dominant effect of the first (most energetic) collapses, however, the model overestimates the importance of smaller nuclei mainly due to their large number in the spectra. Introduction of a threshold for the minimum collapse energy required to form any erosive potential seems necessary to rectify this deficiency. The model, although aimed to achieve efficiency and simplicity by relying on the single-bubble dynamics, shows good agreement with the experimental evidence. An attempt to apply the model to the 3-dimensional geometry of a mixed-flow pump impeller is also presented. This paper is a report on part one of work in progress. In the second part the results of the ongoing pitting tests will be used to develop a model of erosive potential.


    Access

    Access via TIB

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Modeling collapse aggressiveness of cavitation bubbles in hydromachinery


    Additional title:

    Modellierung der Zerfallsaggressivität von Kavitationsblasen in Wasserkraftmaschinen


    Contributors:


    Publication date :

    2009


    Size :

    7 Seiten, 10 Bilder, 1 Tabelle, 17 Quellen



    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English




    Dynamics and Noise Emission of Vortex Cavitation Bubbles

    Choi, J. / Hsiao, C.-T. / Chahine, G.L. et al. | British Library Conference Proceedings | 2007


    Simulation of Cavitation Bubbles in Travelling Acoustic Waves

    Koch, P. / Mettin, R. / Lauterborn, W. | British Library Conference Proceedings | 2004


    Broadband Noise of the Cavitating Marine Propellers: Generation and Collapse of the Free Bubbles Downstream of the Fixed Cavitation

    Matusiak, J. / United States; Office of Naval Research; Fluid Dynamics Program / Society of Naval Architects of Korea et al. | British Library Conference Proceedings | 1994


    Modeling and Detecting Aggressiveness From Driving Signals

    Rodríguez González, A B | Online Contents | 2014


    Modeling and Detecting Aggressiveness From Driving Signals

    Rodriguez Gonzalez, Ana Belen / Wilby, Mark Richard / Vinagre Diaz, Juan Jose et al. | IEEE | 2014