Compressible two-phase viscous flow investigations of cavitation dynamics for the ittc standard cavitator

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Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2020-10-07
Major/Subject
Mcode
Degree programme
Language
en
Pages
23
1-23
Series
Applied Sciences (Switzerland), Volume 10, issue 19
Abstract
In this paper, the ITTC Standard Cavitator is numerically investigated in a cavitation tunnel. Simulations at different cavitation numbers are compared against experiments conducted in the cavitation tunnel of SVA Potsdam. The focus is placed on the numerical prediction of sheet-cavitation dynamics and the analysis of transient phenomena. A compressible two-phase flow model is used for the flow solution, and two turbulence closures are employed: a two-equation unsteady RANS model, and a hybrid RANS/LES model. A homogeneous mixture model is used for the two phases. Detailed analysis of the cavitation shedding mechanism confirms that the dynamics of the sheet cavitation are dictated by the re-entrant jet. The break-off cycle is relatively periodic in both investigated cases with approximately constant shedding frequency. The CFD predicted sheet-cavitation shedding frequencies can be observed also in the acoustic measurements. The Strouhal numbers lie within the usual ranges reported in the literature for sheet-cavitation shedding. We furthermore demonstrate that the vortical flow structures can in certain cases develop striking cavitating toroidal vortices, as well as pressure wave fronts associated with a cavity cloud collapse event. To our knowledge, our numerical analyses are the first reported for the ITTC standard cavitator.
Description
Keywords
Compressible two-phase flow, Hydrodynamic cavitation, System instabilities, Turbulence modelling
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Citation
Viitanen , V M , Sipilä , T , Sánchez-Caja , A & Siikonen , T 2020 , ' Compressible two-phase viscous flow investigations of cavitation dynamics for the ittc standard cavitator ' , Applied Sciences (Switzerland) , vol. 10 , no. 19 , 6985 , pp. 1-23 . https://doi.org/10.3390/app10196985