Numerical simulation of the sheet/cloud cavitation around a two-dimensional hydrofoil using a modified URANS approach

Cavitating flow over a two-dimensional Clark-Y hydrofoil is numerically investigated via a Modified density correction method (MDCM) for turbulence closure to improve the capability of two-phase flow simulation for the k-ε RNG turbulence model. A transport equation model for the local volume fraction of vapor is solved, and a modified version of the Kunz model is used for the condensation and evaporation processes. Simulations have been conducted for various cavitation numbers ranging from non-cavitating to cloud cavitation. We compared the time-averaged lift and drag coefficients, cavitation dynamics, and time-averaged velocity profiles with the available experimental data for the MDCM and Density correction method (DCM). The comparisons between numerical and experimental results show that the MDCM and DCM are capable of capturing the special trends of the lift coefficient at the inception cavitation stage and the drag coefficient at the cloud cavitation stage. The MDCM is more robust and physical than the DCM in predicting the wake flow downstream from the trailing edge. The predicted attached cavities of both models almost show the same trend near the leading edge of the hydrofoil. However, the MDCM predicts more shedding cavity than the DCM in the wake region.