Numerical simulation of cavitating turbulent flow in a high head Francis turbine at part load operation with OpenFOAM

The paper presents numerical analysis of cavitating turbulent flow in a high head Francis turbine at part load operation. Analysis was performed by OpenFOAM code. Thekω−SST turbulence model is employed in the Reynolds averaged Navier–Stokes equations in this study. A mixture assumption and a finite rate mass transfer model was introduced. The computing domain includes the spiral casing, the guide vanes, the runner, and the draft tube, which is discretized with a full three-dimensional mesh system of unstructured tetrahedral shapes. The finite volume method is used to solve the governing equations of the mixture model and the pressure-velocity coupling is handled via a Pressure Implicit with Splitting of Operators(PISO) procedure. The tendency of the cavitating flow in the runner and draft tube agrees well with the turbine empirical results.