Numerical validation of two cavitating hydrofoil profiles using the VOF homogeneous mixture approach

The Volume of Fluid homogeneous mixture approach coupled with a cavitation model is used in this work to perform numerical simulations on hydrofoils. A comparison between the complete and the asymptotic cavitation models is first made. The various cavitation models offered in Star-CCM+ and Fluent are then compared and validated using two experimental cases where attached cavitation was reported. The first case focuses on a static rectangular foil made with a modified NACA-0009 section at various cavitation numbers. The vapor bubble length, the pressure distribution and the hydrodynamic forces are compared to the experimental data with satisfactory agreement. The second case simulates an oscillating NACA 16-012 foil in cavitating conditions where the pitch about mid-chord is varied around 5° ± 5° in a sinusoidal manner. The unsteady hydrodynamics of this second case adds challenges to the numerical simulations. The cyclic lift coefficient is compared with the experimental results. A specific case of vapor bubble collapse with a significant impact on lift is investigated in this work. The presentation concludes with some numerical recommendations for proper spatial and temporal discretizations for cavitation simulations and discusses the impact of the models' growth and collapse scaling factors.