A Compressible Model for Cavitating Flow: Comparison between Euler, RANS and LES Simulations

Paper i proceeding, 2012

We present computations of cavitating flow over a NACA15 hydrofoil. The simulations are performed by a finite volume compressible Euler/Navier-Stokes model based on the equilibrium assumption. 2D computations were made for inviscid, one LES and two RANS solutions. Both the Euler and the LES simulations gave reasonable shedding frequencies and cavity lengths. Of the two RANS models, the k − ω SST gave acceptable shedding frequencies, while the Spalart-Allmaras model showed a completely wrong shedding behaviour. 3D simulations were performed for the Euler and LES models. The Euler model showed problems in creating a glossy sheet cavity at the leading edge as jets and vortices broke up the cavity already from the onset. The LES model gave a more stable sheet cavity, but both models predicted too low shedding frequency.