Cavitation is a complex multiphase phenomenon characterised by vapour bubbles forming due to a sudden pressure drop and is often accompanied by increased hull vibrations, increased radiated noise and decrease in propeller and impeller performance. Although the Reynolds-Averaged Navier-Stokes (RANS) method coupled with a cavitation model is still considered a practical tool to predict cavitating flows owing to its computational efficiency, it is unable to predict the unsteadiness of vapor shedding and over-predicts the eddy viscosity. To improve the prediction, an empirical eddy viscosity correction, [Reboud et al. 1998] was proposed to consider the compressibility effects produced by cavitation. Additionally, a new type of models termed as hybrid RANS-Large Eddy Simulation (LES) models have also been recently introduced in the community, having the ability to behave as a RANS or a LES model in different regions of the flow in order to combine the computational cost efficiency of RANS with the accuracy of LES modelling.However, there exists a lack of a comprehensive review of various such turbulence models like the k-ω Shear Stress Transport Model (SST), k-ω SST Scale-adaptive Simulation (SAS), k-ω SST Detached Eddy Simulation (DES), k-ω SST Delayed Detached Eddy Simulations (DDES), Filter-Based Method (FBM) and Partially-Averaged Navier Stokes Method (PANS) to predict cavitating flows. In this work, we conduct such a review to compare their ability to predict cloud cavitating flows by comparing them with x-ray experimental data in a venturi. It is shown that with mesh

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Cavitation is defined as the formation of bubbles resulting from a sharp drop in vapor pressure at a near constant liquid temperature. Both numerical and experimental methods are needed to study this phenomenon in detail. On the numerical side, the cavitation-turbulence coupling in the process makes cavitating flows difficult to model. One particular approach, using a homogeneous Transport-Equation Model (TEM) coupled with a turbulence model has been utilized in this study where the influence of a hybrid RANS-LES turbulence model on the turbulence properties and its ability to behave as an LES model properly is investigated. The Detached Eddy Simulation (DES), Delayed DES (DDES) and Improved DDES (IDDES) are coupled with the Merkle cavitation model to simulate cloud cavitating flow inside a venturi using interPhaseChangeFoam, a multiphase flow solver in OpenFOAM. Comparisons are made for void fraction and turbulence properties on the global and local scale by comparing them with high-fidelity data obtained from X-ray Particle Image Velocimetry (PIV) experiments.