## 5 Conclusions
For the case with the higher cavitation number, the two-equation turbulence model predicted a steady attached sheet cavitation, whereas the hybrid RANS/LES model predicted a highly transient sheet-cavitation shedding being on a par with the experiments. We attributed this difference to the eddy-viscosity modelling. In this case, detailed vortical structures around the foil and the shedding mechanisms of the sheet cavitation were inhibited due to the unsteady RANS modelling approach. Recently we have investigated the Reynolds number sensitiveness of different cavitation types observed on a ship's propeller [31]. For the case of static hydrofoils exhibiting similar phenomena as shown here, this remains to be assessed. Moreover, the ability of an asymptotic mass-transfer model coupled to the compressible flow solver to predict the shock wave dynamics, which can have an effect on the upstream cavitation dynamics [1], remains an open issue. One alternative is to include the Rayleigh-Plesset equation, which takes the bubble dynamics better into account, to the flow model for a more complete physical description of the two-phase flow. Other options to achieve better results comprise more holistic modelling approaches that can better account for the phase change physics, such as inhomogeneous or multi-scale flow models. An extended model of the former type is under development by the authors, and we have obtained promising initial results of propeller cavitation using such an approach. Conceptualization, V.M.V., T.S. ([PERSON]), A.S.-C. and T.S. ([PERSON]); methodology, V.M.V. and T.S. ([PERSON]); software, V.M.V. and T.S. ([PERSON]); validation, V.M.V. ; formal analysis, V.M.V. ; investigation, V.M.V. ; resources, V.M.V. and T.S. ([PERSON]); data curation, V.M.V. and T.S. ([PERSON]); writing--original draft preparation, V.M.V. ; writing--review and editing, T.S. ([PERSON]), A.S.-C. and T.S. ([PERSON]); visualization, V.M.V. ; supervision, T.S. ([PERSON]), A.S.-C. and T.S. ([PERSON]); project administration, T.S. ([PERSON]); funding acquisition, T.S. ([PERSON]). All authors have read and agreed to the published version of the manuscript. [PERSON] would like to express his gratitude for the support granted by the Finnish Funding Agency for Innovation (TEKES) and the German Federal Ministry for Economic Affairs and Energy within the project \"PropNoise\". Without the funding the research project could not have been realized. The APC was funded by VTT. The authors would like to express their gratitude to [PERSON] and [PERSON] from SVA Potsdam GmbH for providing the experimental results and photographs. The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results. The following abbreviations are used in this manuscript:  
CFD Computational fluid dynamics  
DES Detached-eddy simulation  
DDES Delayed DES  
ITTC International Towing Tank Committee  
LE Leading edge  
LES Large eddy simulation  
MUSCL Monotonic upstream-centered scheme for conservation lawsRANS  
Reynolds-averaged Navier-Stokes  
SST  
Shear stress transport  
TE  
Trailing edge  
Unsteady RANS