Abstract: In fluid flow hydrodynamics, one of the limitations is the cavitation phenomenon. Thus, it is crucial to predict accurately the onset of cavitation and somewhat after that. However, most of the simulations that have been reported till now; do not show satisfactory predictions, particularly for initial to sheet/cloud cavitation. In the present study, four cavitation models inclusive of Singhal, Zwart, Kunz, Sauer, and also three recent improved RANS turbulence models including k-kl-, SST k-, and SST Transition are examined for initial to cloud cavitation flows. Hence, the cavitating flow over a two-dimensional ClarkY11.7% hydrofoil at angles of attack 8 and 10 degrees and Reynolds number of 8×105, is numerically studied by means of Ansys-Fluent, and the results are compared against experimental data in a range of cavitation numbers of (0.8-4). It has been tried a great deal, to increase the accuracy of all implemented methods and techniques. Comparisons show that the numerical predictions could be improved considerably. Especially, using the combination of Zwart cavitation and Transient ????−????????−???? turbulence models leads to much better agreement with experimental results for these conditions of flow. Further, the unsteady flow dynamics and pressure variations of different points on the hydrofoil against time have been illustrated.

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