NUMERICAL SIMULATION OF CAVITATING FLOW AROUND A 2D HYDROFOIL:

This paper presents a numerical study of the flow around a 2D hydrofoil, proposed as a test case for the CAV2003 workshop on physical models and CFD tools for computation of cavitating flows. Non-cavitating and cavitating conditions are investigated. The phenomenon of cavitation is modelled through a single fluid model, associated with an arbitrary barotropic state law. The non-cavitating study focuses on the influence of the turbulence model and on the dependence of the results to the mesh used in the computations. The results predicted by three different turbulence models (Baldwin-Lomax, Spalart-Allmaras and k-ε with extended wall function) are compared. The cavitating study first presents an unsteady behaviour of the partial cavity attached to the foil. A quasi-periodic shedding of vapour clouds is observed and in depth analysed. Then, an analysis of a supercavitating condition is performed. NOMENCLATURE c: chord length Cµ: turbulent viscosity coefficient f: main frequency of cavity self-oscillation k: turbulent kinetic energy P: static pressure Pref: outlet static pressure (imposed) Pvap: vapour pressure Uref: inlet velocity (imposed) V: vapour volume ε: turbulent dissipation µt: turbulent viscosity ρ: density ρl, ρv: liquid and vapour density non-dimensional parameters: α: void ratio ld: reduced (by c) abscissa of cavity detachment lmax: reduced (by c) cavity length tmax: reduced (by c) cavity thickness ltmax: reduced (by c*lmax) position of maximum cavity thickness σ: cavitation parameter 2