Numerical Simulation of Cavitating Flow Around a Hydrofoil

Abstract

The objective of this paper is to evaluate the applicability of different cavitation models and determine appropriate numerical parameters for cavitating flows around a hydrofoil. The simulations are performed for a NACA 66 foil at 6 degrees angle of attack, Reynolds number of 750 000 and for a cavitation number of 1.49 corresponding to the partial sheet cavitating regime. The incompressible, multiphase Reynolds-averaged Navier-Stokes (RANS) equations are solved by the CFD solver CFX with Kubota and Merkle cavitation models. As part of the work, the Merkle model is implemented into CFX by User Fortran code because this model has shown good cavitation prediction capability according to the literature. The effects of the k-ε and SST turbulence models on the cavitating flow dynamics are compared. Also, an investigation on structured and hybrid meshes with different mesh sizes and concentrations is carried out in order to better understand the mesh influence for this cavitation simulation. The local compressibility effect is considered by correcting the turbulent eddy viscosity inside the mixture vapor/liquid zones. The numerical results are validated by experiments conducted in a cavitation tunnel at the French Naval Academy.

Investigation of Cavitation Models for Steady and Unsteady Cavitating Flow Simulation

“…The aim is to predict the pressure fluctuations on the cavitating hydrofoil with a good numerical precision and to understand the influence of different cavitating regimes on the hydrofoil dynamics. The present work is an extension to the results presented in two recent ASME [1] and IAHR [2] conferences. The two transport-based cavitation models studied and presented in this paper are named here as the Kubota model and the Merkle model for simplicity.…”