Keywords: turbulence modelling, transport equations, mesh quality, vapour pocket, growth, collapse, steady flow, unsteady flow, k–epsilon modified, NACA0009, hydrofoil NACA66mod, cavitating flow, flow modelling, evaporation, condensation, CFD, computational fluid dynamics
Modelling of unsteady cavitating flow
A 2D numerical model is proposed in this paper to simulate unsteady cavitating flows around hydrofoil NACA66mod. The objective of this study is to define a numerical procedure to model the unsteady cavitating flow. The Reynolds–averaged Navier–Stokes equations are solved for the liquid and vapour mixture, which is considered as a single fluid with variable density which is expressed as function of the vapour volume fraction. The closure of this variable is provided by the transport equation with a source term TEM. The processes of evaporation and condensation are governed by changes in pressure within the flow. The source term is implanted in the CFD code ANSYS CFX v12. The influence of numerical and physical parameters is presented in detail. The numerical simulations are in good agreement with the experimental data for steady and unsteady flow around the hydrofoil.