Numerical analysis was performed for a draft tube flow of a hydraulic turbine. Special attention has been paid for the friction effect through the flow inside the complex geometry of the draft tube, and for the interaction between the vortex structures and the draft tube volute. A draft tube affected could have a large significance on the performance prediction of hydraulic turbines, even on the efficiency of a hydroelectric center. The turbulent model has been applied a standard κ-ε two

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... ns model and the two-dimensional Reynolds Averaged Navier-Stokes (RANS) equations, are discredited with the second order upwind scheme. The SIMPLE algorithm, which is developed using control volumes, is adopted as the numerical procedure. Calculations were performed for a wide variation of runner velocities. The results reveal that with increasing of the runner velocity, the velocity decreases and the static pressure increases, justifying the total recuperation of kinetic energy at the draft tube outlet. Comparison of numerical results with the experimental data available in the literature is satisfactory.