... Abstract At off-design operations, flow instabilities such as vortex breakdown, reverse flows, and stagnant regions are observed in Francis turbines. The present work shows the numerical flow field investigations of a Francis turbine at two different part loads (PL) by employing a vortex...

... Abstract Large Eddy Simulations (LES) are carried out for a Francis turbine operating at an ultra-low load with and without injection. The flow rate of the turbine is 40% of the design value. The injection aims to improve turbine operation for the already unstable base case away from the design...

... Abstract Computational fluid dynamics simulations are conducted to characterize the spatial and temporal characteristics of the flow field inside a Francis turbine operating in the excess load regime. A high-fidelity Large Eddy Simulation (LES) turbulence model is applied to investigate...

... Francis turbine is widely employed in large scale hydro-power stations in the world with main characteristics of efficiency, stability and cavitation. In practical establishment, each large power station must develop a new Francis turbine for its special natural condition and requirement...

... for this Francis Turbine using numerical approach. A well validated commercial software was used to capture cavitation occurring. The paper describes the approach used and presents results in the form of cavitation, occurring or not occurring, by choosing two operating zones on either side of the safe operating...

... 30 07 2010 The unsteady flow behavior and pressure fluctuations in the runner of a Francis turbine were predicted numerically for the middle-low head at three small guide vane openings. The unsteady Reynolds-averaged Navier-Stokes equations with the k–ω based SST turbulence model...

... The 3-D unsteady Reynolds averaged Navier-tokes equations based on the pseudo-homogeneous flow theory and a vapor fraction transport-equation that accounts for non-condensable gas are solved to simulate cavitating flow in a Francis turbine. The calculation results agreed with experiment data...

... and experiment results shows that they both are in good agreement, and it demonstrates that variation of all the parameters of the hydraulic turbine can be forecast accurately during the transient process. runaway transient unsteady simulation pressure fluctuation Francis turbine CProceedings...