Investigation of three-dimensional effects on a cavitating Venturi flow

•An unsteady 3D cavitation sheet is computed with DES and SAS turbulence models.•2D and 3D computations are performed and compared with experimental results.•The 3D computations put in evidence a low frequency, which is absent from 2D computations.•The low frequency is in agreement with recent experimental analysis.

A numerical investigation of the behaviour of a cavitation pocket developing along a Venturi geometry has been performed using a compressible one-fluid hybrid RANS/LES solver. The interplay between turbulence and cavitation regarding the unsteadiness and structure of the flow is complex and not well understood. This constitutes a determinant point to accurately simulate the dynamic of sheet cavities. Various turbulent approaches are tested: a new Scale-Adaptive model and the Detached Eddy Simulation. 2D and 3D simulations are compared with the experimental data. An oblique mode of the sheet is put in evidence.