A numerical study on the performance characteristics of low head Francis turbine with different turbulence models

A Francis hydro turbine can be used in large as well as small hydro power plant. Due to complex flow phenomenon in turbine, deriving a hydrodynamic behaviour of flow through experimentation is a tedious job. These phenomena such as flow separation around turbine blade, pressure drop in runner and draft tube, etc. can be captured through a numerical study. A numerical approach needs turbulence modelling to capture fluctuating component of flow variables. In view of that, a comprehensive study has been carried out to find the sensitiveness of various turbulence modelling on the stability of numerical solution. In present study, three different turbulence models such as Standard k-ε, Standard k-ω and SST model have been considered. To carried out this study, three different loading conditions have been chosen i.e. part-load, BEP and over-load condition. This study has been carried out by using ANSYS CFX (18.1) CFD solver.