Abstract
We present results of Large-eddy simulations (LES) modeling of steady sheet and unsteady cloud cavitation on a two-dimensional hydrofoil which are validated against Particle image velocimetry (PIV) data. The study is performed for the angle of attack of 9° and high Reynolds numbers ReC of the order of 106 providing a strong adverse pressure gradient along the surface. We employ the Schnerr–Sauer and Kunz cavitation models together with the adaptive mesh refinement in critical flow regions where intensive phase transitions occur. Comparison of the LES and visualization results confirms that the flow dynamics is adequately reproduced in the calculations. To correctly match averaged velocity distributions, we propose a new methodology based on conditional averaging of instantaneous velocity fields measured by PIV which only provides information on the liquid phase. This approach leads to an excellent overall agreement between the conditionally averaged fields of the mean velocity and turbulence intensity obtained experimentally and numerically. The benefits of second-order discretization schemes are highlighted as opposed to the lower-order TVD scheme.
Highlights
The regime with the higher Reynolds number is considered first as it corresponds to unsteady cloud cavitation, which may be more suitable for the chosen Large-eddy simulations (LES) model
We presented results of Large-eddy simulations of transitional sheet and unsteady cloud cavitation flow regimes around a 2D hydrofoil at the angle of attack of 9◦ and high Reynolds numbers ReC = 1.19 × 106 and 1.32 × 106 in comparison with the Particle image velocimetry (PIV)
The comparison of LES and visualization results confirmed that the flow dynamics in the unsteady cloud cavitation regime was correctly reproduced in the numerical simulations including the shedding frequencies of partial and full detachment of cloud cavities and typical U-shaped front of the cavitation sheet closure after the cavity breakup
Summary
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. TVD schemes [47,48,49,50] For both RANS and LES, one has to employ the Favre averaging [51] for variable density flows to keep the governing equations in a standard form, this results in extra unclosed terms. This aspect is left unnoticed in literature when numerical and experimental results are compared.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
